Flexible reduced pressure treatment appliance

ABSTRACT

A wound treatment appliance is provided for treating all or a portion of a wound. In some embodiments, the appliance comprises an impermeable flexible overlay that covers all or a portion of the wound for purposes of applying a reduced pressure to the covered portion of the wound. In other embodiments, the wound treatment appliance also includes a vacuum system to supply reduced pressure to the wound in the area under the flexible overlay. In yet other embodiments, the wound treatment appliance also includes wound packing means to prevent overgrowth of the wound or to encourage growth of the wound tissue into an absorbable matrix comprising the wound packing means. In still other embodiments, the appliance may include a suction drain. In other embodiments, the appliance may include a collection chamber to collect and store exudate from the wound. In yet other embodiments, a suction bulb may be used to provide a source of reduced pressure to an impermeable overlay that covers all or a portion of the wound. Finally, methods are provided for using various embodiments of the wound treatment appliance.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No. 11/064,813, filed on Feb. 24, 2005, which claims the benefit of U.S. provisional application No. 60/573,655, filed on May 21, 2004. The full disclosure of these two patent applications is hereby incorporated by reference as if fully set forth herein.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention generally relates to treatment of wounds, and more specifically to an improved apparatus and method for treating all or a portion of a wound on a body by applying reduced pressure to the portion of the wound for which treatment is desired. In this context, the terms “wound” and “body” are to be interpreted broadly, to include any body part of a patient that may be treated using reduced pressure.

The treatment of open or chronic wounds that are too large to spontaneously close or otherwise fail to heal by means of applying reduced pressure to the site of the wound is well known in the art. One such system is disclosed in U.S. patent application Ser. No. 10/652,100, which was filed by the present inventor with the U.S. Patent and Trademark Office on Aug. 28, 2003. The disclosure of this U.S. patent application is incorporated herein by reference. Another system is disclosed in a U.S. patent application entitled “Improved Reduced Pressure Wound Treatment Appliance,” which was filed by the present inventor with the U.S. Patent and Trademark Office on or about Dec. 30, 2004. The disclosure of this U.S. patent application is also incorporated herein by reference.

Reduced pressure wound treatment systems currently known in the art commonly involve placing a cover that is impermeable to liquids over the wound, using various means to seal the cover to the tissue of the patient surrounding the wound, and connecting a source of reduced pressure (such as a vacuum pump) to the cover in a manner so that an area of reduced pressure is created under the cover in the area of the wound. However, the covers currently known and used in the art have a number of disadvantages. For example, in one version they tend to be in the form of a flexible sheet of material that is placed over the wound and sealed to the surrounding tissue using an adhesive, adhesive tape, or other similar means. As tissue swelling in the area of the wound decreases during the healing process, the adhesive may begin to stretch the surrounding tissue, as well as tissue within the wound, resulting in discomfort and pain to the patient. This may necessitate more frequent cover changes, increasing the time medical staff must expend in treating the wound. This additional time, of course, also tends to increase the expense involved in treating the wound. In addition, these types of covers can typically only be used where there is normal tissue adjacent to the wound to which the adhesive seal can be attached. Otherwise, the seal must be made in a portion of the area of the wound, and exudate from the wound tends to break the seal so that reduced pressure cannot be maintained beneath the wound cover. Thus, such covers (and many other covers requiring adhesive seals) may typically only be used to treat an entire wound, as opposed to only a portion of a wound. Further, the adhesive seal creates discomfort for the patient when the sheet cover is removed. In other versions, the covers tend to be rigid or semi-rigid in nature so that they are held away from the surface of the wound. In these versions, the covers are sometimes difficult to use because the shape and contour of the patient's body in the area of the wound do not readily adapt to the shape of the cover. In such cases, additional time is required for the medical staff to adapt the cover for its intended use. This also increases the expense of wound treatment. In addition, it is also often necessary to use an adhesive, adhesive tape, or other similar means to seal the rigid or semi-rigid cover to the tissue surrounding the wound. In these instances, the same disadvantages discussed above with respect to the first version also apply to this version as well. In still other cases, the rigid and semi-rigid covers must be used with padding in the area where the cover is adjacent to the patient to prevent the edges of the cover from exerting undue pressure on the tissue surrounding the wound. Without the padding, the patient may experience pain and discomfort. The additional padding, which may make the cover itself more expensive, may also take a greater amount of time to place on the patient for treatment purposes. These covers may also have the problem of placing tension on the surrounding tissue as the swelling in the area of the wound decreases during the healing process. In yet another version, covers are constructed of combinations of flexible materials and rigid materials. In these versions, a flexible member, such as a flexible sheet, is typically supported by a rigid or semi-rigid structure that is either placed between the flexible member and the wound or in the area above and outside the flexible member. In either case, the flexible member must usually be sealed to the tissue surrounding the wound using an adhesive, adhesive tape, or other similar means. This seal creates the same problems described above. In addition, the same problems described above with respect to rigid and semi-rigid structures are also often present. In all of the versions described above, it may be difficult to tell if reduced pressure in the area of the wound under the cover has been lost because the cover itself does not generally provide a visual clue of such loss.

Therefore, there is a need for a reduced pressure wound treatment system that has a means to enclose all or a portion of a wound without the need for an adhesive seal. There is also a need for such enclosing means to be flexible, so that it adapts to changing shapes and contours of the patient's body as wound healing progresses. Further, there is a need for an enclosing means that is adaptable to a wide variety of patient body shapes and contours. There is also a need for an enclosing means that is simple to apply to the patient's body, and simple to remove from the patient's body. Such enclosing means would also take less time to apply and remove, reducing the expense involved in wound treatment. There is also a need for an enclosing means that is relatively inexpensive, while meeting the needs described above. In addition, there is a need for an enclosing means that may be used within the wound (or a portion thereof), without the need to seal the enclosing means to normal tissue surrounding the wound. Further, there is a need for an enclosing means that flexes with movement of the portion of the body surrounding the wound, without the need for an adhesive seal or rigid or semi-rigid structure. Finally, there is a need for an enclosing means that provides a visual clue of loss of reduced pressure in the area of the wound under the enclosing means.

SUMMARY OF THE INVENTION

The present invention is directed to a reduced pressure wound treatment appliance and methods that satisfy the needs described above. As described in greater detail below, they have many advantages over existing reduced pressure wound treatment apparatus and methods when used for their intended purpose, as well as novel features that result in a new reduced pressure wound treatment appliance and methods that are not anticipated, rendered obvious, suggested, or even implied by any of the prior art apparatus or methods, either alone or in any combination thereof.

In accordance with the present invention, a wound treatment appliance is provided for treating all or a portion of a wound by applying reduced pressure (i.e., pressure that is below ambient atmospheric pressure) to the portion of the wound to be treated in a controlled manner for a selected time period in a manner that overcomes the disadvantages of currently existing apparatus. The application of reduced pressure to a wound provides such benefits as faster healing, increased formation of granulation tissue, closure of chronic open wounds, reduction of bacterial density within wounds, inhibition of burn penetration, and enhancement of flap and graft attachment. Wounds that have exhibited positive response to treatment by the application of negative pressure include infected open wounds, decubitus ulcers, dehisced incisions, partial thickness burns, and various lesions to which flaps or grafts have been attached.

In a first aspect of a first version of the present invention, the wound treatment appliance is comprised of an impermeable flexible overlay and reduced pressure supply means, which are described in more detail below and are used to connect the flexible overlay to a reduced pressure supply source that provides a supply of reduced pressure to the flexible overlay. In this first aspect of the first version of the invention, the flexible overlay is adapted to be placed over and enclose all or a portion of a wound on the surface of the body of a patient. The flexible overlay is also adapted to maintain reduced pressure under the flexible overlay in the area of the wound. The flexible overlay collapses in the approximate direction of the area of the wound to be treated when reduced pressure is supplied to the volume under the flexible overlay in the area of the wound. This collapse causes the formation of an approximately hermetic seal (described in more detail below) between the flexible overlay and the body in the area of the wound. In some embodiments of this first aspect of the first version of the invention, the flexible overlay is further comprised of an interior surface facing the area of the wound to be treated, wherein the surface area of the interior surface is greater than the surface area of the portion of the body to be enclosed by the flexible overlay. In other embodiments of this first aspect of the first version of the invention, the flexible overlay is further comprised of a bottom portion having an approximately elongated conical shape with an approximately elliptically-shaped open end at the base of the elongated conical bottom portion. In these embodiments, the approximately elliptically-shaped open end at the base is sized to be placed over and enclose the area of the wound to be treated. In yet other embodiments of this first aspect of the first version of the invention, the flexible overlay (as opposed to only the bottom portion thereof) has an approximately elongated conical shape having an approximately elliptically-shaped open end at its base. In these embodiments, the approximately elliptically-shaped perimeter of the open end at the base of the flexible overlay is positioned over all or a portion of the wound on the surface of the body. In some of these embodiments, the flexible overlay further comprises a port located approximately at the apex of the elongated conically-shaped flexible overlay. In these embodiments, the reduced pressure supply means is operably connected to the port. In yet other embodiments of this first aspect of the first version of the invention, the flexible overlay is comprised of at least three cover portions, each of such cover portions being approximately triangular in shape. One point of each of the at least three triangular-shaped cover portions are joined to form an apex of the flexible overlay and one side of each at least three triangular-shaped cover portions adjacent to the apex is joined to an adjacent side of another of such at least three triangular-shaped cover portions so that the bases of the at least three triangular-shaped cover portions form an opening sized to be placed over and enclose the area of the wound to be treated. In some of these embodiments, the flexible overlay is further comprised of a port located approximately at the apex of the flexible overlay and the reduced pressure supply means is operably connected to the port. In still other embodiments of this first aspect of the first version of the invention, at least one fold forms in the surface of the flexible overlay when it collapses, so that fluids aspirated by the wound flow along the at least one fold to the reduced pressure supply means, where they are removed from the flexible overlay by means of the reduced pressure supply means cooperating with the reduced pressure supply source. In other embodiments, the appliance further comprises supplemental sealing means, which are described in more detail below, to form a seal between the flexible overlay and the body in the area of the wound. In yet other embodiments, the appliance further comprises a suction drain and suction drain connecting means, which are described in more detail below, to operably connect the reduced pressure supply means to the suction drain so that the suction drain is in fluid communication with the reduced pressure supply means and reduced pressure is supplied to the volume under the flexible overlay in the area of the wound by means of the suction drain. The suction drain extends from the reduced pressure supply means into the volume under the flexible overlay in the area of the wound.

In a second aspect of the first version of the present invention, the wound treatment appliance is comprised of a wound treatment device and a vacuum system. In this second aspect of the first version of the invention, the vacuum system is further comprised of a reduced pressure supply source that provides a supply of reduced pressure and reduced pressure supply means to operably connect the wound treatment device to the reduced pressure supply source, so that the volume under the wound treatment device in the area of the wound is supplied with reduced pressure by the reduced pressure supply source. In various embodiments of this second aspect of the first version of the invention, the wound treatment device and the reduced pressure supply means may generally have substantially the same structure, features, characteristics and operation as the appliance described above in connection with the first aspect of the first version of the invention.

In some embodiments of this second aspect of the first version of the invention, the reduced pressure supply source is comprised of a vacuum pump. In some of these embodiments, the reduced pressure supply source further comprises a control system for the vacuum pump, wherein the control system may control at least the level of suction produced by the vacuum pump or the rate of fluid flow produced by the vacuum pump, or any combination of rate of suction and rate of fluid flow of the vacuum pump. In other embodiments, the reduced pressure supply source further comprises a filter operably positioned between the vacuum pump and the reduced pressure supply means. In these embodiments, the filter prevents the venting of and contamination of the vacuum pump by micro-organisms aspirated from the wound or fluids aspirated from the wound or both. In yet other embodiments, the vacuum pump is comprised of a portable vacuum pump. In still other embodiments of this second aspect of the first version of the invention, the reduced pressure supply means is comprised of flexible tubing. In other embodiments, the reduced pressure supply means is further comprised of a collection system that is operably positioned between the wound treatment device and the reduced pressure supply source. In some of these embodiments, the collection system comprises a container to receive and hold fluid aspirated from the wound and pressure halting means to halt the application of reduced pressure to the wound when the fluid in the container exceeds a predetermined amount. In other embodiments of this second aspect of the first version of the invention, the reduced pressure under the flexible overlay in the area of the wound is in the range from approximately 20 mm of Hg below atmospheric pressure to approximately 125 mm of Hg below atmospheric pressure. In yet other embodiments, the reduced pressure is applied in a cyclic nature, the cyclic nature providing alternating time periods of application of reduced pressure and without application of reduced pressure. In some embodiments of this second aspect of the first version of the invention, the wound treatment appliance further comprises tissue protection means, which are described in more detail below, to protect and strengthen the body tissue that is adjacent to the flexible overlay at the wound site. In some of these embodiments, the tissue protection means is a hydrocolloid material.

In a third aspect of the first version of the invention, the wound treatment appliance is comprised of a wound treatment device, a vacuum system, and wound packing means, which are described in more detail below, that are positioned between the wound treatment device and the portion of the wound to be treated. In various embodiments of this third aspect of the first version of the invention, the wound treatment device and the vacuum system may generally have substantially the same structure, features, characteristics and operations as the wound treatment device and the vacuum system, respectively, described above in connection with the second aspect of the first version of the invention. In this third aspect of the first version of the invention, the flexible overlay of the wound treatment device is placed over all or a portion of the wound and the wound packing means when the flexible overlay is positioned on the surface of the body at the wound site. In some embodiments of this third aspect of the first version of the invention, the wound packing means is comprised of absorbent dressings, antiseptic dressings, nonadherent dressings, water dressings, or combinations of such dressings. In some of these embodiments, the wound packing means is preferably comprised of gauze or cotton or any combination of gauze and cotton. In still other embodiments, the wound packing means is comprised of an absorbable matrix adapted to encourage growth of the tissue in the area of the wound under the flexible overlay into the matrix. The absorbable matrix is constructed of an absorbable material that is absorbed into the epithelial and subcutaneous tissue in the wound as the wound heals. Because of the absorbable nature of the absorbable matrix, the matrix should require less frequent changing than other dressing types during the treatment process. In other circumstances, the matrix may not need to be changed at all during the treatment process. In some of these embodiments, the absorbable matrix is comprised of collagen or other absorbable material. In some embodiments of this third aspect of the first version of the invention, the appliance further comprises a suction drain and suction drain connecting means, which are described in more detail below, to operably connect the reduced pressure supply means to the suction drain so that the suction drain is in fluid communication with the reduced pressure supply means and reduced pressure is supplied to the volume under the impermeable flexible overlay in the area of the wound by means of the suction drain. In these embodiments, the suction drain extends from the reduced pressure supply means into the volume under the impermeable flexible overlay in the area of the wound. In some of these embodiments, the suction drain is further comprised of a distal end portion and the distal end portion has at least one perforation in the surface thereof. In some of these embodiments, the distal end portion of the suction drain is positioned within the interior volume of the wound packing means.

In a fourth aspect of the first version of the invention, the wound treatment appliance is comprised of a wound treatment device and a vacuum system. In various embodiments of this fourth aspect of the first version of the invention, the wound treatment device is comprised of an impermeable overlay and a seal. The impermeable overlay is sized to be placed over and enclose the area of the wound to be treated and is adapted to maintain reduced pressure in the area of the wound to be treated. The seal seals the impermeable flexible overlay to the body in the area of the wound in a manner so that reduced pressure is maintained under the impermeable overlay in the area of the wound to be treated. In addition, in the various embodiments of this fourth aspect of the first version of the invention, the vacuum system is comprised of a suction bulb, which may (but not necessarily) provide a source of reduced pressure, and reduced pressure supply means, which are described in more detail below, to operably connect the impermeable overlay to the suction bulb, so that the area of the wound under the impermeable overlay may be supplied with reduced pressure by the suction bulb. In some embodiments of this fourth aspect of the first version of the invention, the impermeable overlay is comprised of a rigid or semi-rigid wound cover. In other embodiments, the impermeable overlay is comprised of a flexible wound cover. In some of these embodiments, the flexible wound cover may be comprised of a flexible overlay that has substantially the same structure, features, characteristics and operation as the flexible overlay described above in connection with the first aspect of this first version of the invention. In some embodiments of this fourth aspect of the first version of the invention, the suction bulb is further comprised of an inlet port and an outlet port, wherein the inlet port is operably connected to the reduced pressure supply means, and the vacuum system further comprises an exhaust tubing member operably connected to the outlet port. In some of these embodiments, the vacuum system further comprises an exhaust control valve operably connected to the exhaust tubing member. In other embodiments, the vacuum system is further comprised of a filter operably connected to the exhaust tubing member, which prevents the venting of micro-organisms aspirated from the wound or fluids aspirated from the wound or both. In yet other embodiments, the vacuum system is further comprised of a supplemental vacuum system that is operably connected to the exhaust tubing member. In these embodiments, the supplemental vacuum system may generally have substantially the same structure, features, characteristics and operation as the vacuum system described above in connection with the second and third aspects of the first version of the invention.

A fifth aspect of the first version of the present invention discloses a method of treating a wound on a body. In one embodiment of this fifth aspect of the first version of the invention, the method comprises the following steps. First, positioning an flexible overlay on the body over the area of the wound to be treated, wherein the flexible overlay is sized to be placed over and enclose the area of the wound to be treated and adapted to maintain reduced pressure in the area of the wound to be treated. Second, operably connecting the flexible overlay with a vacuum system for producing reduced pressure in the volume under the flexible overlay in the area of the wound to be treated. Third, collapsing the flexible overlay in the approximate direction of the wound when reduced pressure is supplied to the volume under the flexible overlay in the area of the wound so that an approximately hermetic seal (described in more detail below) is formed between the impermeable flexible overlay and the body in the area of the wound. Fourth, maintaining the reduced pressure until the area of the wound being treated has progressed toward a selected stage of healing. In other embodiments of this fifth aspect of the first version of the invention, the method further comprises the step of placing tissue protection means on the tissue of the body that is to be approximately adjacent to the flexible overlay, such step being performed prior to positioning the flexible overlay over the area of the wound to be treated. The tissue protection means, which is described in more detail below, protects and strengthens the tissue of the body adjacent to the flexible overlay at the wound site. In yet other embodiments of this fifth aspect of the first version of the invention, the method further comprises the step of placing wound packing means (described in more detail above) between the wound and the flexible overlay in the area of the wound to be treated, such step being performed prior to positioning the flexible overlay over the area of the wound to be treated. In still other embodiments of this fifth aspect of the first version of the invention, the vacuum system is comprised of a suction bulb and the method further comprises the step of squeezing the suction bulb to reduce its volume and then releasing the suction bulb, so that reduced pressure is produced in the volume under the flexible overlay in the area of the wound. In other embodiments of this fifth aspect of the first version of the invention, the reduced pressure under the impermeable overlay in the area of the wound is in the range from approximately 20 mm of Hg below atmospheric pressure to approximately 125 mm of Hg below atmospheric pressure. In still other embodiments of this fifth aspect of the first version of the invention, the reduced pressure is applied in a cyclic nature, the cyclic nature providing alternating time periods of application of reduced pressure and without application of reduced pressure.

As is illustrated in the detailed descriptions herein, the wound treatment appliance of the present invention meets the needs discussed above in the Background section. For example, in the preferred embodiment of a flexible overlay having a bottom portion with an approximately elongated conical shape, the flexible overlay is placed over and encloses all or a portion of the wound. When the flexible overlay is enclosing all or a portion of the wound, the portions of the flexible overlay positioned adjacent to the surface of the body at the wound site are at (or can be deformed to be at) a relatively acute angle relative to such surface of the body. When reduced pressure is applied to the area under the flexible overlay, the flexible overlay is drawn downward, collapsing the flexible overlay in the approximate direction of the wound. As the flexible overlay collapses, the portions of the flexible overlay adjacent to the perimeter of the opening of the flexible overlay are drawn tightly against the surface of the body at the wound site, thus forming an approximately hermetic seal. References to an “approximately hermetic seal” herein refer generally to a seal that is gas-tight and liquid-tight for purposes of the reduced pressure treatment of the wound. It is to be noted that this seal need not be entirely gas-tight and liquid-tight. For example, the approximately hermetic seal may allow for a relatively small degree of leakage, so that outside air may enter the volume under the flexible overlay in the area of the wound, as long as the degree of leakage is small enough so that the vacuum system can maintain the desired degree of reduced pressure in the volume under the flexible overlay in the area of the wound. In some uses where the collapsing flexible overlay may not produce an approximately hermetic seal that is solely capable of maintaining the reduced pressure in the volume under the impermeable overlay in the area of the wound, it may be necessary to provide supplemental sealing means, which are described in more detail below, and which are used to provide a seal between the portions of the flexible overlay and the body where the approximately hermetic seal is not adequate. As a result, the flexible overlay is simple to apply to the patient. There is also often no need for any other sealing means in most cases, which means that there is usually no need for medical staff to take the time to make a separate seal. Even where the geometry of the surface of the body surrounding the wound may require that supplemental sealing means be used to provide some limited assistance to ensure a seal, the amount of such assistance (such as by applying an adhesive) is limited, especially when compared to current covers in the art. In addition, as swelling of tissue at the wound site decreases, the flexible nature of the flexible overlay allows it to further deform to conform to the changing shape and contours at the wound site. This prevents the patient from being discomforted as the swelling decreases. It also reduces the need to change the covering over the wound as healing progresses. This is generally not true in cases involving flexible, semi-rigid and rigid covers that exist in the art. For example, even where semi-rigid and rigid covers do not utilize an adhesive seal and rely solely upon the reduced pressure to hold them in place, they do not generally change shape enough to flex with substantial changes in the shape and contour of the surrounding body surface. Thus, they may not be appropriate for use with body portions that are subject to such changes, while the flexible nature of the flexible overlay, along with its increased surface area that can bend and flex, allow it to be used in such circumstances without the need for an adhesive seal. In the same way, the flexible overlay may generally be used for unusual geometries of the body at or surrounding the wound because of the overlay's flexible nature and relatively large surface area. In contrast, flexible sheets and semi-rigid and rigid covers may require substantial modification and means to provide an adequate seal. In addition, such covers may require that the patient be partially or wholly immobilized during the treatment process to avoid movement in the area of the body surrounding the wound to avoid breaking the seal. And such covers must usually be sealed to normal tissue surrounding the wound. The flexible overlay, however, may be used within the perimeter of a wound in many cases because there is not typically a need to seal the flexible overlay to normal tissue surrounding the wound. Further, because there is typically no need for an adhesive seal, removal of the flexible overlay merely requires removal of the reduced pressure from the area under the flexible overlay. It is thus simple to remove from the patient. For this reason, it will tend to reduce the time required of medical staff for wound treatment, which will also tend to reduce the cost of wound treatment. In addition, there is no pain and discomfort for the patient when the flexible overlay is removed. Even if a limited amount of supplemental sealing means (such as an adhesive) are required to provide a seal at a portion of the flexible overlay that is adjacent to the surface surrounding the wound, the reduced amount of supplemental sealing means will cause a corresponding reduction in the amount of such pain and discomfort. Further, the preferred embodiments of the collapsed flexible overlay will have folds in its surface while in the collapsed state, so that fluid aspirated by the wound may flow along the folds to be removed from under the flexible overlay. In addition, if reduced pressure is lost under the flexible overlay, the flexible overlay will expand outward from the wound, providing a visual indication that reduced pressure has been lost. Finally, in its preferred embodiments, the flexible overlay is relatively inexpensive to manufacture, even though it meets the described needs.

In a first aspect of a second version of the present invention, the wound treatment appliance is comprised of a fluid impermeable flexible overlay, a collection chamber to receive and hold fluid aspirated from the wound, collection chamber attachment means to operably attach the collection chamber to the flexible overlay, as described in more detail below, and reduced pressure supply means, which are described in more detail below. In this first aspect of the second version of the invention, the flexible overlay is adapted to be placed over and enclose all or a portion of the wound. In the various embodiments of this first aspect of the second version of the invention, except as described in more detail below, the flexible overlay has substantially the same structure, features characteristics and operation as the flexible overlay described above in connection with the first aspect of the first version of the invention. In addition, in this first aspect of the second version of the invention, the reduced pressure supply means is used to operably connect the collection chamber to a reduced pressure supply source that provides a supply of reduced pressure to the collection chamber, so that the volume within the collection chamber and under the impermeable overlay in the area of the wound to be treated are supplied with reduced pressure by the reduced pressure supply source. In the various embodiments of this second version of the invention, except as described in more detail below, the reduced pressure supply means to connect the reduced pressure supply source to the collection chamber in the embodiments of this second version of the invention may have substantially the same structure, features, characteristics and operation as the reduced pressure supply means described above in connection with the first version of the invention.

In this first aspect of the second version of the invention, the flexible overlay is attached by collection chamber attachment means to a collection chamber that receives and holds fluid aspirated from the wound. In some embodiments, the collection chamber may be approximately cylindrical in shape. In the various embodiments of this first aspect of the second version of the invention, the collection chamber attachment means operably attaches the collection chamber to the flexible overlay in a manner so that the fluid and reduced pressure are permitted to flow between the collection chamber and the volume under the flexible overlay in the area of the wound. In some embodiments of this first aspect of the second version of the invention, the collection chamber is positioned approximately adjacent to the impermeable flexible overlay on the side of the impermeable flexible overlay opposite the wound and the collection chamber attachment means is a rigid or semi-rigid connecting member positioned between the collection chamber and the impermeable flexible overlay. In these embodiments, the connecting member has a port therein that extends between the collection chamber and the flexible overlay. In embodiments where the flexible overlay is approximately elongated-conically shaped, the collection chamber and the collection chamber attachment means may be positioned approximately at the apex of the flexible overlay on the side of the impermeable flexible overlay opposite the wound. In some embodiments, the collection chamber may be approximately cylindrical in shape. In other embodiments, the collection chamber attachment means may be further comprised of a flow control means, which is described in more detail below, operably positioned between the collection chamber and the flexible overlay. In these embodiments, the flow control means permit the fluid to flow from the volume under the flexible overlay in the area of the wound into the collection chamber, but not in the opposite direction. In some of these embodiments, the flow control means may be comprised of a valve. In some of these embodiments, the valve may be comprised of a flapper-type valve. In yet other embodiments, the collection chamber is positioned approximately adjacent to the impermeable flexible overlay on the side of the impermeable flexible overlay opposite the wound and the collection chamber attachment means is comprised of a membrane. In these embodiments, the membrane acts as a barrier separating the collection chamber and the impermeable flexible overlay, so that the membrane acts as a portion of the surface of the collection chamber and a portion of the surface of the impermeable flexible overlay. In addition, the membrane has at least one port therein so that the volume within the collection chamber is in fluid communication with the volume under the impermeable flexible overlay in the area of the wound. In embodiments where the impermeable flexible overlay has an approximately conical shape or approximately elongated conical shape, the impermeable flexible overlay may have a base end opening and a top end opening opposite the base end opening. In these embodiments, the base end opening may have an either approximately circular shape or approximately elliptical shape sized to be placed over and enclose the area of the wound to be treated. The top end opening may have either an approximately circular shape or approximately elliptical shape. In these embodiments, the membrane is sized to be of the same shape and size as the top end opening and the membrane is positioned so that it is attached to the entire perimeter of the top end opening and covers the entire top end opening. In some embodiments, the collection chamber may have an approximately conical shape or approximately elongated conical shape with a chamber bottom end opening and a reduced pressure supply port positioned at the apex of the collection chamber opposite the chamber bottom end opening. In various embodiments, the chamber bottom end opening may have an either approximately circular shape or approximately elliptical shape adapted to be of approximately the same size and shape as the top end opening of the impermeable flexible overlay. In some of these embodiments, the perimeter of the chamber bottom end opening is attached to the membrane in a manner so that the collection chamber is airtight, except for the port in the membrane and the reduced pressure supply port. The reduced pressure supply port operably connects the reduced pressure supply means to the collection chamber. In some embodiments, the collection chamber attachment means is further comprised of flow control means operably connected with the at least one port, wherein the flow control means permits fluid aspirated from the wound to flow from the volume under the impermeable flexible overlay in the area of the wound through the at least one port to the collection chamber, but not in the opposite direction. In some of these embodiments, the flow control means is comprised of a valve. Preferably, this valve is comprised of a flapper-type valve.

In a second aspect of the second version of the present invention, the wound treatment appliance is comprised of a wound treatment device and a vacuum system, which is further comprised of a reduced pressure supply source that provides a supply of reduced pressure and reduced pressure supply means to operably connect the wound treatment device to the reduced pressure supply source. In various embodiments of this second aspect of the second version of the invention, except as described below, the wound treatment device and the reduced pressure supply means may generally have substantially the same structure, features, characteristics and operations as the appliance described above in connection with the first aspect of the second version of the invention. In these embodiments, the reduced pressure supply means operably connect the wound treatment device to the reduced pressure supply source so that the volume within the collection chamber and under the wound treatment device in the area of the wound is supplied with reduced pressure by the reduced pressure supply source.

In some embodiments of this second aspect of the second version of the invention, the reduced pressure supply source is comprised of a vacuum pump. In some of these embodiments, the reduced pressure supply source further comprises a control system for the vacuum pump, wherein the control system controls the operation of the vacuum pump. In other embodiments, the reduced pressure supply source further comprises a filter operably positioned between the vacuum pump and the reduced pressure supply means. In these embodiments, the filter prevents the venting of and contamination of the vacuum pump by micro-organisms aspirated from the wound or fluids aspirated from the wound or both. In yet other embodiments, the vacuum pump is comprised of a portable vacuum pump. In still other embodiments, the reduced pressure supply means is comprised of flexible tubing. In other embodiments of this second aspect of the second version of the invention, the reduced pressure under the flexible overlay in the area of the wound is in the range from approximately 20 mm of Hg below atmospheric pressure to approximately 125 mm of Hg below atmospheric pressure. In yet other embodiments, the reduced pressure is applied in a cyclic nature, the cyclic nature providing alternating time periods of application of reduced pressure and without application of reduced pressure. In some embodiments of this second aspect of the second version of the invention, the wound treatment appliance further comprises tissue protection means, which are described in more detail below, to protect and strengthen the body tissue that is adjacent to the flexible overlay at the wound site. In some of these embodiments, the tissue protection means is a hydrocolloid material. In still other embodiments, wound packing means, which are described in more detail herein, are positioned between the wound treatment device and the portion of the wound to be treated.

A third aspect of the second version of the present invention discloses a method of treating a wound on a body. In one embodiment of this third aspect of the second version of the invention, the method comprises the following steps. First, a wound treatment device is positioned on the body over the area of the wound to be treated, wherein the wound treatment device is comprised of an impermeable flexible overlay, a collection chamber, and collection chamber attachment means, which are described in more detail below. In this embodiment, the flexible overlay is sized to be placed over and enclose the area of the wound to be treated and adapted to maintain reduced pressure in the area of the wound to be treated. In addition, in this embodiment, the collection chamber receives and holds fluid aspirated from the wound and the collection chamber attachment means, which is described in more detail below, operably attaches the collection chamber to the impermeable flexible overlay in a manner so that reduced pressure and the fluid are permitted to flow between the collection chamber and the impermeable flexible overlay. Second, the collection chamber is operably connected with a vacuum system for producing reduced pressure in the volume within the collection chamber and in the volume under the flexible overlay in the area of the wound to be treated. Third, the flexible overlay is collapsed in the approximate direction of the wound when reduced pressure is supplied to the volume under the flexible overlay in the area of the wound so that an approximately hermetic seal (described in more detail herein) is formed between the impermeable flexible overlay and the body in the area of the wound. Fourth, reduced pressure is maintained until the area of the wound being treated has progressed toward a selected stage of healing. In other embodiments of this third aspect of the first version of the invention, the method further comprises the step of placing tissue protection means on the tissue of the body that is to be approximately adjacent to the impermeable flexible overlay, such step being performed prior to positioning the impermeable flexible overlay over the area of the wound to be treated. The tissue protection means, which is described in more detail below, protects and strengthens the tissue of the body adjacent to the flexible overlay at the wound site. In yet other embodiments of this third aspect of the first version of the invention, the method further comprises the step of placing wound packing means (described in more detail herein) between the wound and the impermeable flexible overlay in the area of the wound to be treated, such step being performed prior to positioning the impermeable flexible overlay over the area of the wound to be treated. In still other embodiments of this third aspect of the first version of the invention, the reduced pressure under the impermeable overlay in the area of the wound is in the range from approximately 20 mm of Hg below atmospheric pressure to approximately 125 mm of Hg below atmospheric pressure. In still other embodiments of this third aspect of the first version of the invention, the reduced pressure is applied in a cyclic nature, the cyclic nature providing alternating time periods of application of reduced pressure and without application of reduced pressure.

There has thus been outlined, rather broadly, the more primary features of the present invention. There are additional features that are also included in the various embodiments of the invention that are described hereinafter and that form the subject matter of the claims appended hereto. In this respect, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the following drawings. This invention may be embodied in the form illustrated in the accompanying drawings, but the drawings are illustrative only and changes may be made in the specific construction illustrated and described within the scope of the appended claims. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of the description and should not be regarded as limiting.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing summary, as well as the following detailed description of the preferred embodiments of the present invention, will be better understood when read in conjunction with the appended drawings, in which:

FIG. 1A is a perspective view of an embodiment of an impermeable flexible overlay of a wound treatment appliance of a first version of the present invention, as viewed from the side of and above the flexible overlay comprising the wound treatment appliance (as the flexible overlay would be oriented when placed on the body of a patient);

FIG. 1B is a perspective view of another embodiment of an impermeable flexible overlay of a wound treatment appliance of the first version of the present invention, as viewed from the side of and above the flexible overlay comprising the wound treatment appliance (as the flexible overlay would be oriented when placed on the body of a patient);

FIG. 1C is a perspective view of another embodiment of an impermeable flexible overlay of a wound treatment appliance of the first version of the present invention, as viewed from the side of and above the flexible overlay comprising the wound treatment appliance (as the flexible overlay would be oriented when placed on the body of a patient);

FIG. 2A is a view of an embodiment of a wound treatment appliance of the first version of the present invention, in which an embodiment of an impermeable flexible overlay, shown in perspective view from the side of and above the flexible overlay, covers a wound, and in which an embodiment of a vacuum system, depicted generally and shown in schematic elevation view, provides reduced pressure within the area under the flexible overlay;

FIG. 2B is a sectional elevational detailed view of an embodiment of a collection container and the shutoff mechanism portion of the collection system of FIG. 2A;

FIG. 3 is a view of an embodiment of a wound treatment appliance of the first version of the present invention, in which an embodiment of an impermeable flexible overlay, shown in cross-sectional elevational view from the side of the flexible overlay, covers a wound and wound packing means, and in which an embodiment of a vacuum system, shown in elevational view, provides reduced pressure within the area under the flexible overlay;

FIG. 4 is a view of an embodiment of a wound treatment appliance of the first version of the present invention, in which an embodiment of an impermeable flexible overlay, shown in cross-sectional elevational view from the side of the flexible overlay, covers a wound, and in which an embodiment of a vacuum system, shown in perspective view from the side of and below the vacuum system, provides reduced pressure within the area under the flexible overlay; and

FIG. 5 is a view of an embodiment of a wound treatment appliance of a second version of the present invention, in which an embodiment of an impermeable flexible overlay, shown in perspective view from the side of and above the flexible overlay, covers a wound, and in which an embodiment of a vacuum system, depicted generally and shown in schematic elevation view, provides reduced pressure within the area under the flexible overlay.

FIG. 6 is a view of another embodiment of a wound treatment appliance of a second version of the present invention, in which an embodiment of an impermeable flexible overlay is shown in partially broken away perspective view from the side of and above the flexible overlay (as the flexible overlay would be oriented when placed on the body of a patient), and in which an embodiment of a vacuum system, depicted generally and shown in schematic elevation view, provides reduced pressure within the area under the flexible overlay.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In accordance with the present invention, a wound treatment appliance is provided for treating all or a portion of a wound by applying reduced pressure (i.e., pressure that is below ambient atmospheric pressure) to the portion of the wound to be treated in a controlled manner for a selected time period in a manner that overcomes the disadvantages of currently existing apparatus. One embodiment of a first aspect of a first version of the invention is a wound treatment appliance 10 that is comprised of the fluid impermeable flexible overlay 20 illustrated in FIG. 1A and reduced pressure supply means, which are described in more detail below. In this embodiment, the flexible overlay 20 has an approximately elongated conical shape, having an opening 21 with an opening perimeter 22 adjacent to the opening 21 (at the base of the elongated conical shape) that is approximately elliptical in shape. The flexible overlay 20 illustrated in FIG. 1A is in its natural shape, as it exists prior to being applied to a patient for treatment of all or a portion of a wound. In other embodiments, the flexible overlay 20 may have other shapes. For example, the flexible overlay 20 may be approximately conical in shape, rather than the approximately elongated conical shape illustrated in FIG. 1A. As another example, as illustrated in FIG. 1B, only the bottom portion 23 a of the flexible overlay 20 a may have an approximately elongated conical shape. In this embodiment, and in the same manner as illustrated in FIG. 1A, the bottom portion 23 a has an opening 21 a with an opening perimeter 22 a adjacent to the opening 21 a (at the base of the elongated conical shape) that is approximately elliptical in shape. In the embodiment of the flexible overlay illustrated in FIG. 1B, the top portion 24 a is flatter than the comparable portion of the flexible overlay 20 in the embodiment illustrated in FIG. 1A. In other embodiments, the top portion 24 a of the flexible overlay 20 a may have almost any shape that is adaptable to a bottom portion 23 a having an approximately elongated conical shape. In addition, in yet other embodiments of this first aspect of the first version of the invention, the bottom portion 23 a of the flexible overlay 20 a may be in the approximate shape of a cone, rather than the elongated conical shape illustrated in FIG. 1B. In yet another embodiment, as illustrated in FIG. 1C, the flexible overlay 20 b is comprised of six cover portions 23 b, 23 b′, where the cover portions 23 b are viewable in FIG. 1C and the cover portions 23 b′ are illustrated by phantom lines. In this embodiment, each of such cover portions 23 b, 23 b′ is approximately triangular in shape, and one point of each of the at least three cover portions 23 b, 23 b′ is joined to form an apex 24 b of the impermeable flexible overlay 20 b. One side of each cover portion 23 b, 23 b′ adjacent to the apex 24 b is joined to an adjacent side of another of such cover portions 23 b, 23 b′ so that the bases 22 b, 22 b′ of the cover portions 23 b, 23 b′, respectively, form an opening 21 b sized to be placed over and enclose the area of the wound to be treated. In other embodiments, the flexible overlay 20 b may have a different number of cover portions 23 b, 23 b′. Preferably, in these embodiments, there are at least three cover portions 23 b, 23 b′. In addition, in yet other embodiments, the flexible overlay 20 b may have cover portions 23 b, 23 b′ having a different shape, such as trapezoidal or parabolic. In still other embodiments, the flexible overlay 20, 20 a, 20 b may be of almost any shape that may be adaptable for treating all or a portion of a wound, as long as the flexible overlay 20, 20 a, 20 b is flexible, as described in more detail below, and the interior surface of the flexible overlay 20, 20 a, 20 b is adapted to make an approximately hermetic seal with the body of the patient at the site of the wound, as described in more detail below. Referring again to FIG. 1A as an example, in some embodiments of this first aspect of the first version of the invention, the interior surface of the flexible overlay 20 is adapted to make an approximately hermetic seal with the body of the patient at the site of the wound by having a surface area larger than the surface area of the portion of the body of the patient covered by the flexible overlay 20, as described in more detail below.

The preferred shape and size of the flexible overlay 20, 20 a, 20 b is dependent upon the size of the portion of the wound to be treated, the shape and contour of the portion of the body that is to be covered by the flexible overlay 20, 20 a, 20 b at the site of the wound, the magnitude of the reduced pressure to be maintained under the flexible overlay 20, 20 a, 20 b. More preferred, as illustrated in FIG. 1B, the flexible overlay 20 a has an approximately elongated conically shaped bottom portion 23 a. Most preferred, as illustrated in FIG. 1A, the flexible overlay 20 is shaped approximately as an elongated cone. The preferred thickness of the portion 25, 25 a, 25 b of the flexible overlay 20, 20 a, 20 b adjacent to the open end 21, 21 a, 21 b of the flexible overlay 20, 20 a, 20 b is dependent upon the size and shape of the flexible overlay 20, 20 a, 20 b, the shape and contour of the portion of the body that is to be covered by the flexible overlay 20, 20 a, 20 b at the site of the wound, the magnitude of the reduced pressure to be maintained under the flexible overlay 20, 20 a, 20 b, and other factors, such as the depth of the wound and the amount of the desired collapse of the flexible overlay 20, 20 a, 20 b. For example, in the embodiment illustrated in FIG. 1A, for a flexible overlay 20 constructed of silicone and having an approximately elongated conical shape with an opening 21 having a major diameter of approximately 7 inches and a minor diameter of approximately 4 inches, the preferred thickness of the portion 25 of the flexible overlay 20 adjacent to the open end 21 of the flexible overlay 20 is in the range from ( 1/32) inches to ( 3/32) inches. More preferred in this embodiment, the thickness of the portion 25 of the flexible overlay 20 adjacent to the open end 21 of the flexible overlay 20 is approximately ( 1/16) inches. It is to be noted that in other embodiments the thickness of the flexible overlay 20, including the portion 25 of the flexible overlay 20 adjacent to the open end 21 of the flexible overlay 20, may vary from location to location on the flexible overlay 20.

In the embodiment of the flexible overlay 20 illustrated in FIG. 1A, the flexible overlay 20 has a series of raised beads 26 on the outside surface of the flexible overlay 20. In this embodiment, the raised beads 26 are generally parallel to the perimeter 22 of the opening 21 of the flexible overlay 20. The same is also true of the raised bead 26 b of the flexible overlay 20 b of the embodiment illustrated in FIG. 1C. In other embodiments, such as that illustrated in FIG. 1B, the raised beads 26 a may have a different orientation. In still other embodiments, the raised beads 26, 26 a, 26 b may be in almost any orientation desired by the user of the wound treatment appliance 10, 10 a, 10 b. In various embodiments of this first aspect of the first version of the invention, as illustrated in FIG. 1A, the raised beads 26 may provide a guide for the user administering the reduced pressure treatment to cut away a portion of the flexible overlay 20, so that the perimeter 22 of the opening 21 of the flexible overlay 20 is smaller than it was originally. For example, by cutting along the parallel raised beads 26 of the flexible overlay 20 of FIG. 1A, the size of the opening 21 of the flexible overlay 20 can be made smaller while the shape of the perimeter 22 remains approximately the same. It is to noted, however, that in various embodiments of this first aspect of the first version of the invention, as described in more detail below, the flexible overlay 20 may be cut into different shapes in order to adapt the flexible overlay 20 for use with different shapes and contours of the surface of the body at the site of the wound.

In the various embodiments of this first aspect of the first version of the invention, the flexible overlay 20, 20 a, 20 b may be comprised of almost any medical grade flexible material that is currently known in the art or that may be developed in the art in the future, as long as such material is fluid-impermeable, suitable for purposes of wound treatment (e.g., can be sterilized and does not absorb significant amounts of wound exudate), and is capable of forming an approximately hermetic seal with the surface of the body at the site of the wound, as described in more detail below. For example, the flexible overlay 20, 20 a, 20 b may be comprised of rubber (including neoprene), and flexible polymer materials, such as silicone, silicone blends, silicone substitutes, polyester, vinyl, polyimide, polyethylene napthalate, polycarbonates, polyester-polycarbonate blends, or a similar polymer, or combinations of all such materials. Preferably, the flexible overlay 20, 20 a, 20 b is comprised of silicone. Although the raised beads 26, 26 a, 26 b may be constructed of a material different from the material comprising the remainder of the flexible overlay 20, 20 a, 20 b in various embodiments of the invention, the raised beads 26, 26 a, 26 b are preferably constructed from the same material comprising the remainder of the flexible overlay 20, 20 a, 20 b. In other embodiments, the raised beads 26, 26 a, 26 b may be placed on the flexible overlay 20, 20 a, 20 b by means of a mark, such as indelible ink, on the surface of the flexible overlay 20, 20 a, 20 b. It is to be noted that in various embodiments of this first aspect of the first version of the invention, the flexible overlay 20, 20 a, 20 b may be constructed in whole or in part of gas-permeable materials, allowing limited amounts of oxygen to penetrate the flexible overlay 20, 20 a, 20 b so that the area of the wound under the flexible overlay 20, 20 a can “breathe.” It is also to be noted that all portions of the flexible overlay 20, 20 a, 20 b are preferably constructed of one type of polymer material, such as silicone. The flexible overlay 20, 20 a, 20 b may be constructed using any suitable means currently known in the art or that may be developed in the art in the future. For example, a flexible overlay 20, 20 a, 20 b constructed of silicone may be manufactured by means of injection molding.

In the embodiments of the flexible overlay 20, 20 a, 20 b illustrated in FIG. 1A, FIG. 1B, and FIG. 1C, respectively, each of the flexible overlays 20, 20 a, 20 b further comprises a port 27, 27 a, 27 b adapted to receive a reduced pressure supply means to supply reduced pressure to the area of the wound under the flexible overlay 20, 20 a, 20 b. Although the port 27 is positioned at approximately the apex of the elongated cone-shaped flexible overlay 20 in the embodiment illustrated in FIG. 1A, and the port 27 b is positioned at approximately the apex 24 b of the triangular-shaped cover portions 23 b, 23 b′ in the embodiment illustrated in FIG. 1C, which is the preferred location, the port may be located at another location on the flexible overlay in other embodiments. In such embodiments, and referring to FIG. 1B as an example, the port 27 a (and alternate port 27 a′) may be located at almost any location on the surface of the flexible overlay 20 a as long as the port 27 a, 27 a′ does not adversely affect the ability of the flexible overlay 20 a to make an approximately hermetic seal with the surface of the body at the wound site, as described in more detail below. For example, the port 27 a, 27 a′ may not be located too close to the perimeter 22 a of the opening 21 a of the flexible overlay 20 a because the approximately hermetic seal with the surface of the body is typically formed at that location. In the embodiment of the flexible overlay 20 a illustrated in FIG. 1B, the alternate port 27 a′ may preferably be located at any location on the top portion 24 a of the flexible overlay 20 a, and more preferably, the port 27 a is located at the center of the top portion 24 a of the flexible overlay 20 a. Referring again to FIG. 1A as an example, although the port 27 may be constructed of a material different from the material comprising the remainder of the flexible overlay 20 in various embodiments of the invention, the port 27 is preferably constructed from the same material comprising the remainder of the flexible overlay 20. In the embodiments of the flexible overlay 20, 20 a, 20 b illustrated in FIG. 1A, FIG. 1B, and FIG. 1C, respectively, the ports 27, 27 a, 27 b are generally cylindrical in shape and are further comprised of an approximately cylindrical channel 28, 28 a, 28 b, respectively, that extends from the top of each of the ports 27, 27 a, 27 b, respectively, to the bottom of the ports 27, 27 a, 27 b, respectively. The ports 27, 27 a, 27 b of these embodiments are thus able to receive a vacuum system or reduced pressure supply means, which are described in more detail below, adapted to be connected to this shape of port 27, 27 a, 27 b, respectively, and channel 28, 28 a, 28 b, respectively. In other embodiments of this first aspect of the first aspect of the first version of the invention, the ports 27, 27 a, 27 b or the channels 28, 28 a, 28 b, respectively, or both may have different shapes and configurations as may be desired to adapt and connect the ports 27, 27 a, 27 b, respectively, and the channels 28, 28 a, 28 b, respectively, to the vacuum system or reduced pressure supply means, which are described in more detail below.

An embodiment of a second aspect of the first version of the present invention is the wound treatment appliance 110 illustrated in FIG. 2A. In this embodiment, the wound treatment appliance 110 is comprised of a wound treatment device 115 and a vacuum system, generally designated 150, that is operably connected to, and provides a supply of reduced pressure to, the wound treatment device 115. Also in this embodiment, the wound treatment device 115 is comprised of a flexible overlay 120. In addition, in this embodiment, the vacuum system 150 is further comprised of a reduced pressure supply source, generally designated 130, which is illustrated schematically and described in more detail below, and reduced pressure supply means, generally designated 140, which are illustrated schematically and described in more detail below. Also in this embodiment, the reduced pressure supply means 140 are used to connect the reduced pressure supply source 130 to the flexible overlay 120 in a manner so that reduced pressure is supplied to the volume under the flexible overlay 120 in the area of the wound 160, as described in more detail below. In the embodiment of the second aspect of the first version of the invention illustrated in FIG. 2A, the flexible overlay 120 has substantially the same structure, features, characteristics and operation as the flexible overlay 20 described above and illustrated in connection with FIG. 1A. It is to be noted, however, that in other embodiments of this second aspect of the first version of the invention, the flexible overlay 120 may have substantially the same structure, features and characteristics as any embodiment of all of the flexible overlays 20, 20 a, 20 b of the first aspect of the first version of the invention described above and illustrated in connection with FIG. 1A, FIG. 1B, and FIG. 1C. FIG. 2A also illustrates an example of how the embodiment of the flexible overlay 20 illustrated in FIG. 1A may be used to provide reduced pressure treatment for a wound 160 on the body 170 of a patient. In this example, the flexible overlay 120 is placed over and encloses the entire wound 160, as described in more detail below. In other embodiments, the flexible overlay 120 need not enclose the entire wound 160.

In the embodiment illustrated in FIG. 2A, the reduced pressure supply source 130 of the vacuum system 150, which produces a source of reduced pressure or suction that is supplied to the flexible overlay 120, is comprised of a vacuum pump 131, a control device 132, and a filter 133. Although the preferred means of producing the reduced pressure or suction is a vacuum pump 131 in this embodiment, in other embodiments of this second aspect of the first version of the invention other means may be used, such as an outlet port of a centralized hospital vacuum system. In the illustrated embodiment, predetermined amounts of suction or reduced pressure are produced by the vacuum pump 131. The vacuum pump 131 is preferably controlled by a control device 132, such as a switch or a timer that may be set to provide cyclic on/off operation of the vacuum pump 131 according to user-selected intervals. Alternatively, the vacuum pump 131 may be operated continuously without the use of a cyclical timer. In addition, in some embodiments the control device 132 may provide for separate control of the level of reduced pressure applied to the wound 160 and the flow rate of fluid aspirated from the wound 160. In these embodiments, relatively low levels of reduced pressure may be maintained in the area of the wound 160 under the wound treatment device 115, while still providing for the removal of a relatively large volume of exudate from the wound 160. A filter 133, such as a micropore filter, is preferably attached to the inlet of the vacuum pump 131 to prevent potentially pathogenic microbes or aerosols from contaminating, and then being vented to atmosphere by, the vacuum pump 131. In other embodiments, the filter 133 may also be a hydrophobic filter that prevents any exudate from the wound from contaminating, and then being vented to atmosphere by, the vacuum pump 131. It is to be noted that in other embodiments of the invention, the reduced pressure supply source 130 may not have a filter 133 or a control 132 or any combination of the same.

In the embodiment of the second aspect of the first version of the invention illustrated in FIG. 2A, the reduced pressure supply means 140 of the vacuum system 150, which are used to connect the reduced pressure supply source 130 to the flexible overlay 120 so that reduced pressure is supplied to the volume under the flexible overlay 120 in the area of the wound 160 is comprised of at least one tubing member 141. In this embodiment, the at least one tubing member 141 is sufficiently flexible to permit movement of the at least one tubing member 141, but is sufficiently rigid to resist constriction when reduced pressure is supplied to the flexible overlay 120 or when the location of the wound 160 is such that the patient must sit or lie upon the at least one tubing member 141 or upon the wound treatment device 115. In the embodiment illustrated in FIG. 2A, the at least one tubing member 141 is connected to the flexible overlay 120 by inserting one end of the at least one tubing member 141 into the opening 128 of the port 127 of the flexible overlay 120. In this embodiment, the at least one tubing member is held in place in the opening 128 by means of an adhesive. It is to be noted that in other embodiments of this second aspect of the first version of the invention, the at least one tubing member 141 may be connected to the port 127 of the flexible overlay 120 using any suitable means currently known in the art or developed in the art in the future. Examples include variable descending diameter adapters (commonly referred to as “Christmas tree” adapters), luer lock fittings and adapters, clamps, and combinations of such means. Alternatively, the port 127 and the at least one tubing member 141 may be fabricated as a single piece. Similar means may be used to connect the other end of the at least one tubing member 141 to the vacuum pump 131 or other reduced pressure supply source 130 providing the reduced pressure.

In the embodiment illustrated in FIG. 2A, the reduced pressure supply means 140 further comprises a fluid collection system, generally designated 142, that is interconnected between the suction pump 131 and the flexible overlay 120 to remove and collect any exudate that may be aspirated from the wound 160 and collected by the flexible overlay 120. The flexible overlay 120 functions to actively draw fluid or exudate from the wound 160. Collection of exudate in a fluid collection system 142 intermediate the pump 131 and the flexible overlay 120 is desirable to prevent clogging of the pump 131. The fluid collection system 142 is comprised of a fluid-impermeable collection container 143 and a shutoff mechanism 144, which are described in more detail below in connection with FIG. 2B. The container 143 may be of any size and shape capable of intercepting and retaining a predetermined amount of exudate. Many examples of such containers are available in the relevant art. Referring to FIG. 2B, which is an enlarged elevational cross-sectional view of the preferred embodiment of the container 143, the container 143 includes a first port 143 a at the top opening of the container 143 for sealed connection to tubing member 141 a, where the other end of the tubing member 141 a is connected to the flexible overlay 120. The first port 143 a enables suction to be applied to the flexible overlay 120 through the tubing 141 a and also enables exudate from the portion of the wound 160 covered by the flexible overlay 120 to be drained into the container 143. The container 143 provides a means for containing and temporarily storing the collected exudate. A second port 143 b is also provided on the top of the container 143 to enable the application of suction from the vacuum pump 131. The second port 143 b of the collection system 142 is connected to the vacuum pump 131 by tubing member 141 b. The collection system 142 is sealed generally gas-tight to enable the suction pump 131 to supply suction to the flexible overlay 120 through the collection system 142.

The embodiment of the collection system 142 illustrated in FIG. 2B also includes a shutoff mechanism for halting or inhibiting the supply of the reduced pressure to the flexible overlay 120 in the event that the exudate aspirated from the wound 160 exceeds a predetermined quantity. Interrupting the application of suction to the flexible overlay 120 is desirable to prevent exsanguination in the unlikely event a blood vessel ruptures under the flexible overlay 120 during treatment. If, for example, a blood vessel ruptures in the vicinity of the wound 160, a shut-off mechanism would be useful to prevent the vacuum system 150 from aspirating any significant quantity of blood from the patient. In the preferred embodiment of the shutoff mechanism 144, as illustrated in FIG. 2B, the shutoff mechanism 144 is a float valve assembly in the form of a ball 144 a which is held and suspended within a cage 144 b positioned below a valve seat 144 c disposed within the opening at the top of the container below the second port 143 b that will float upon the exudate and will be lifted against the valve seat 144 c as the container 143 fills with exudate. When the ball 144 a is firmly seated against the valve seat 144 c, the float valve blocks the second port 143 b and thereby shuts off the source of suction from the vacuum system 150. In other embodiments of the container 143, other types of mechanisms may also be employed to detect the liquid level within the container 143 in order to arrest operation of the vacuum system 50. In addition, in various embodiments of this second version of the invention, the shutoff mechanism 144 may be comprised of any means that enables the vacuum system 150 to halt the supply of reduced pressure to the flexible overlay 120 at any time that the volume of exudate from the wound 160 exceeds a predetermined amount. Such means may include mechanical switches, electrical switches operably connected to the vacuum system controller 132, optical, thermal or weight sensors operably connected to the vacuum system controller 132, and any other means that are currently known in the relevant art or that may be developed in the art in the future.

In some embodiments of this second version of the invention, the wound treatment appliance 110 further comprises tissue protection means 175 to protect and strengthen the body tissue 171 that is adjacent to the flexible overlay 120 at the wound site 161. The tissue protection means 175 protects the tissue 171 by preventing abrasion and maceration of the tissue. Preferably, the tissue protection means 175 is a hydrocolloid material, such as COLOPAST Hydrocolloid 2655, anhydrous lanoline, or any combination of such hydrocolloid materials. More preferably, the tissue protection means 175 is COLOPAST Hydrocolloid 2655. The tissue protection means 175 may be applied to the body tissue 171 to be protected, or it may be applied to the surface of the flexible overlay 120 that is to be in contact with the body tissue 171, or both, prior to placing the flexible overlay 120 on the surface of the body 170 at the wound site 161. It is to be noted that application of the tissue protection means 175 to the body tissue 171 that is adjacent to the flexible overlay 120 at the wound site 161 may only entail application of the tissue protection means 175 to the portion of the body tissue 171 adjacent to the flexible overlay 120 that requires such protection.

FIG. 2A also illustrates an example of how the embodiment of the flexible overlay 20 illustrated in FIG. 1A (which is flexible overlay 120 in FIG. 2A) may be used to provide reduced pressure treatment for a wound 160 on the body 170 of a patient. In this example, the flexible overlay 120 is removed from an aseptic package in which it is stored. The flexible overlay 120 is then placed over and encloses the portion of the wound 160 to be treated, which is the entire wound 160 in this example. The flexible overlay 120 is also connected to the vacuum system 150 by means of the port 127 on the flexible overlay 120 either before, after or during the placement of the flexible overlay 120 over the wound 160. Where it is deemed necessary by the user of the wound treatment appliance 110, tissue protection means 175, as described above, may be placed on a portion of the flexible overlay 120, on the body tissue 171 to be protected, or both, prior to placing the flexible overlay 120 over the wound 160. In the example illustrated in FIG. 2A, the interior surface portions 129 of the flexible overlay 120 positioned around and adjacent to the perimeter 122 of the opening 121 of the flexible overlay 120 are at (or can be deformed to be at) a relatively acute angle relative to the surrounding surface of the body 170. Such deformation may be caused by the user of the wound treatment appliance 110 exerting mild pressure on the portions 129 of the flexible overlay 120 positioned around and adjacent to the perimeter 122 of the opening 121 of the flexible overlay 120 so that they are in contact with the surface of the body 170 surrounding the wound 160. Reduced pressure is then supplied to the flexible overlay 120 by the vacuum system 150. When reduced pressure is applied to the volume under the flexible overlay 120 in the area of the wound 160, the flexible overlay 120 is drawn downward by the reduced pressure, collapsing the flexible overlay 120 in the approximate direction of the wound 160. As the flexible overlay 120 collapses, the portions 129 of the flexible overlay 120 adjacent to the perimeter 122 of the opening 121 of the flexible overlay 120 are drawn tightly against the surface of the body 170 surrounding the wound 160, thus forming an approximately hermetic seal between the portions 129 of the flexible overlay 120 adjacent to the perimeter 122 of the opening 121 of the flexible overlay 120 and the portion of the body 170 adjacent to such portions 129. References to an “approximately hermetic seal” herein refer generally to a seal that may be made gas-tight and liquid-tight for purposes of the reduced pressure treatment of the wound 160. It is to be noted that this seal need not be entirely gas-tight and liquid-tight. For example, the approximately hermetic seal may allow for a relatively small degree of leakage, so that outside air may enter the volume under the flexible overlay 120 in the area of the wound 160, as long as the degree of leakage is small enough so that the vacuum system 150 can maintain the desired degree of reduced pressure in the volume under the flexible overlay 120 in the area of the wound 160. As another example, the approximately hermetic seal formed by the collapsing flexible overlay 120 may not be solely capable of maintaining the reduced pressure in the volume under the impermeable overlay 120 in the area of the wound 160 due to the shape of the body 170 at the site of the wound 160 or for other reasons. In these cases, it may be necessary to provide supplemental sealing means, which are used to provide a seal between the portions of the flexible overlay 120 and the body 170 where the approximately hermetic seal is not adequate to permit reduced pressure to be maintained in the volume under the flexible overlay 120 in the area of the wound 160. For example, in the illustrated embodiment, the supplemental sealing means 176 may be an adhesive applied to a portion of the impermeable overlay 120 or a portion of the body 170 in a manner similar to the application of the tissue protection means 175 described above. In other embodiments, the supplemental sealing means 176 may be comprised of almost any suitable means to provide an adequate seal. For example, the supplemental sealing means 176 may be comprised of an adhesive, an adhesive tape, a stretch fabric that covers the wound treatment device 115 and is wrapped around a portion of the body 170 of the patient in the area of the wound 160, lanoline, or any combination of such means. It is also to be noted that in this embodiment at least one fold 129 a forms in the surface of the flexible overlay 120 when it collapses, so that fluids aspirated by the wound 160 flow along the at least one fold 129 a to the port 127, where the fluid is removed from the flexible overlay 120 by means of the reduced pressure supply means 140 cooperating with the reduced pressure supply source 130. Thus, in the preferred embodiments, the impermeable overlay 120 is constructed of a material, and has a size, shape and thickness, that permits the flexible overlay 120 to collapse in the direction of the wound 160 and form an approximately hermetic seal with the body 170 when reduced pressure is applied to the volume under the flexible overlay 120 in the area of the wound 160, while still being rigid enough to support the approximately hermetic seal with the body 170 and to support the at least one fold 129 a. It is also to be noted that the volume under the impermeable overlay 120 in the area of the wound 160 may be minimal while the impermeable overlay 120 is in its collapsed state over the wound 160. In the preferred embodiments of this second aspect of the first version of the invention, the reduced pressure maintained in the volume under the flexible overlay 120 in the area of the wound 160 is in the range from approximately 20 mm of Hg below atmospheric pressure to approximately 125 mm of Hg below atmospheric pressure. In yet other embodiments, the reduced pressure is applied to the flexible overlay 120 in a cyclic nature, the cyclic nature providing alternating time periods of application of reduced pressure and non-application of reduced pressure. In all of these embodiments, the reduced pressure is maintained in the volume under the flexible overlay 120 in the area of the wound 160 until the wound 160 has progressed toward a selected stage of healing.

An embodiment of a third aspect of the first version of the invention is the wound treatment appliance 210 illustrated in FIG. 3. In this embodiment, the wound treatment appliance 210 is comprised of a wound treatment device 215 and a vacuum system, generally designated 250, that is operably connected to, and provides a supply of reduced pressure to, the wound treatment device 215. In addition, in this embodiment, the vacuum system 250 is further comprised of a reduced pressure supply source, generally designated 280, which is described in more detail below, and reduced pressure supply means, generally designated 240, which are described in more detail below. Also in this embodiment, the wound treatment device 215 is further comprised of an impermeable flexible overlay 220, wound packing means 278, and a suction drain 245. In the embodiment of the third aspect of the first version of the invention illustrated in FIG. 3, the flexible overlay 220 has substantially the same structure, features, characteristics and operation as the flexible overlay 20 described above and illustrated in connection with FIG. 1A. It is to be noted, however, that in other embodiments of this third aspect of the first version of the invention, the flexible overlay 220 may have substantially the same structure, features, characteristics and operation as any embodiment of all of the flexible overlays 20, 20 a, 20 b of the first aspect of the first version of the invention described above and illustrated in connection with FIG. 1A, FIG. 1B, and FIG. 1C, respectively. It is also to be noted that in other embodiments the wound treatment device 220 may be comprised of almost any type of flexible, semi-rigid, or rigid wound covering apparatus currently known in the relevant art or that may be developed in the relevant art in the future that has a port and is designed to cover and enclose a wound and maintain reduced pressure in the area of the wound under the wound covering apparatus. For example, the impermeable overlay 220 may generally have substantially the same structure, features and characteristics as the embodiments of the rigid, semi-rigid or flexible wound covers described in U.S. patent application Ser. No. 10/652,100, which was filed by the present inventor with the U.S. Patent and Trademark Office on Aug. 28, 2003, and U.S. patent application entitled “Improved Reduced Pressure Wound Treatment Appliance,” which was filed by the present inventor with the U.S. Patent and Trademark Office on or about Dec. 30, 2004, the disclosures of which are incorporated herein by reference. In these embodiments, the impermeable overlay 220 may be sealed to the body in the area of the wound using any means disclosed in such applications or using the supplemental sealing means 176 described above and illustrated in connection with FIG. 2A. In the embodiment illustrated in FIG. 3, the flexible overlay 220 is placed over and encloses the entire wound 260 and is illustrated in a state of partial collapse, with the portion 229 of the flexible overlay 220 adjacent to the opening 221 in the perimeter 222 of the flexible overlay 220 forming an approximately hermetic seal with the adjacent portions 271 of the body 270. It is to be noted that in various embodiments of this third aspect of the first version of the invention, the wound treatment appliance 210 may also be comprised of tissue protection means 275, which may be substantially the same as the tissue protection means 175 of the second aspect of the first version of the invention described above and illustrated in connection with FIG. 2A.

In the embodiment of the third aspect of the first version of the invention illustrated in FIG. 3, the wound treatment device 215 is further comprised of wound packing means 278, which is placed in the area of the wound 260 under the flexible overlay 220. In this embodiment, the flexible overlay 220 is placed over the area of the wound 260 to be treated and the wound packing means 278 when the flexible overlay 220 is positioned on the surface of the body 270 at the site of the wound 260. In some embodiments of this third aspect of the first version of the invention, the wound packing means 278 may be placed within the wound 260 to prevent overgrowth of the tissue in the area of the wound 260. For example, and preferably in these cases, the wound packing means 278 may comprised of absorbent dressings, antiseptic dressings, nonadherent dressings, water dressings, or combinations of such dressings. More preferably, the wound packing means 278 may be comprised of gauze or cotton or any combination of gauze and cotton. In still other embodiments of this third aspect of the first version of the invention, the wound packing means 278 may be comprised of an absorbable matrix adapted to encourage growth of the tissue in the area of the wound 260 into the matrix. In these embodiments, the absorbable matrix (as wound packing means 278) is constructed of an absorbable material that is absorbed into the epithelial and subcutaneous tissue in the wound 260 as the wound 260 heals. The matrix (as wound packing means 278) may vary in thickness and rigidity, and it may be desirable to use a spongy absorbable material for the patient's comfort if the patient must lie upon the wound treatment device 215 during treatment. The matrix (as wound packing means 278) may also be perforated and constructed in a sponge-type or foam-type structure to enhance gas flow and to reduce the weight of the matrix. Because of the absorbable nature of the absorbable matrix (as wound packing means 278), the matrix should require less frequent changing than other dressing types during the treatment process. In other circumstances, the matrix (as wound packing means 278) may not need to be changed at all during the treatment process. In some embodiments of this third aspect of the first version of the invention, the absorbable matrix (as wound packing means 278) may be comprised of collagens or other absorbable materials or combinations of all such materials. U.S. patent application Ser. No. 10/652,100, which was filed by the present inventor with the U.S. Patent and Trademark Office on Aug. 28, 2003, and is hereby incorporated by reference, also discloses various embodiments of an absorbable matrix that may be utilized with various embodiments of the third aspect of the first version of the present invention. It is to be noted, however, that wound packing means 278 may not be utilized in other embodiments of this third aspect of the first version of the invention.

In the embodiment of the third aspect of the first version of the invention illustrated in FIG. 3, the wound treatment device 215 is also comprised of a suction drain 245 and suction drain connection means, which are described in more detail below, to operably connect the reduced pressure supply means 240 to the suction drain 245 so that the suction drain 245 is in fluid communication with the reduced pressure supply means 240 and reduced pressure is supplied to the volume under the flexible overlay 220 in the area of the wound 260 by means of the suction drain 245. In this embodiment, the suction drain 245 is further comprised of a bottom drain portion 245 a extending into the area of the wound 260 under the impermeable overlay 220 from a top drain portion 245 b positioned within the port 227. In various embodiments, the top drain portion 245 b may be permanently or removably attached to the interior surface of the opening 228 of the port 227 using any suitable means, such as an adhesive, or by the top drain portion 245 b having a shape adapted so that all or a portion of it fits tightly against all or a portion of the interior surface of the opening 228 in the port 227. It is to be noted that the top drain portion 245 b must be sufficiently sealed against the surface of the port 227 in a manner so that reduced pressure can be maintained in the volume under the impermeable overlay 220 in the area of the wound 260. In the embodiment illustrated in FIG. 3, the top drain portion 245 b and the bottom drain portion 245 a of the suction drain 245 are comprised of polymer tubing that is flexible enough to allow the tubing to easily bend, but rigid enough to prevent the tubing from collapsing during use. In other embodiments, portions of the top drain portion 245 b and the bottom drain portion 245 a of the suction drain 245 may be comprised of other materials, such as flexible or semi-rigid polymers, plastics, rubber, silicone, or combinations of such materials. In yet other embodiments, the suction drain 245 may have different cross-sectional shapes, such as elliptical, square, rectangular, pentagonal, hexagonal, or other shapes, as long as the suction drain 245 is adapted to provide an approximately hermetic seal with the port 227, as described in more detail above. In still other embodiments, the bottom drain portion 245 a of the suction drain 245 may be further comprised of wound suction means that may be used to remove debris, exudate and other matter from the wound 260. In the embodiment illustrated in FIG. 3, the wound suction means is comprised of a distal end portion 245 a′ of the tubing comprising the bottom drain portion 245 a having a plurality of perforations 245 a″ in the surface of the distal end portion 245 a′. In other embodiments, the distal end portion 245 a′ of the bottom drain portion 245 a may have almost any shape or combination of shapes (e.g., circular, elliptical, square, pentagonal, or hexagonal), including a shape different from the remaining portion of the bottom drain portion 245 a, may be of almost any size relative to the remaining bottom drain portion 245 a (e.g., may be longer or shorter than the remaining bottom drain portion 245 a or have a cross-section smaller or larger than the remaining bottom drain portion 245 a, or both), may have more or fewer perforations 245 a″, may have different sizes and shapes of perforations 245 a″, may extend along different portions of the bottom drain portion 245 a, and may be constructed in whole or in part of materials that are not flexible. In embodiments that have a distal end portion 245 a′, the distal end portion 245 a′ may be attached to the remaining portion of the bottom drain portion 245 a in almost any manner, as long as the remaining bottom drain portion 245 a is in fluid communication with the wound suction means 245 a′. Examples include an adhesive in some embodiments and a fastening collar in other embodiments. In still other embodiments, the distal end portion 245 a′ may be fused or welded to the remaining portion of the bottom drain portion 245 a. In yet other embodiments, the distal end portion 245 a′ and the remaining portion of the bottom drain portion 245 a may be fabricated as a single piece.

In some embodiments of this first version of the invention, as illustrated in FIG. 3, the top drain portion 245 b may extend beyond the top of the port 227 into the area outside the volume of the flexible overlay 220. In some of these embodiments, as is also illustrated in FIG. 3, the suction drain connection means, which may be used to removably connect the reduced pressure supply means 240 to the top drain portion 245 b of the suction drain 245 is a variable descending diameter adapter 246 (commonly referred to as a “Christmas tree” adapter) that is placed into the interior volume of the top drain portion 245 b at its distal end. In other embodiments, the suction drain connection means may be clamps, fastening collars, or other fasteners or combinations thereof. In yet other embodiments, the top drain portion 245 b may be fused or welded to the reduced pressure supply means 240. In still other embodiments, the top drain portion 245 b and the portion of the reduced pressure supply means 240 adjacent to the top drain portion 245 b may be fabricated as a single piece. In other embodiments, the top drain portion 245 b may not extend beyond the top of the port 227 and the reduced pressure supply means 240 may connect directly to the port 227 using any suitable means, such as an adhesive, welding, fusing, clamps, collars or other fasteners, or any combination of such means.

In the embodiment of this third aspect of the first version of the invention illustrated in FIG. 3, the distal end portion 245 a′ of the suction drain 245 extends into the interior volume of the wound packing means 278. In this embodiment, the wound packing means 278 and the suction drain 245 may be fabricated by snaking the distal end portion 245 a′ of the suction drain 245 through an internal passageway in the wound packing means 278, such as by pulling the distal end portion 245 a′ of the suction drain 245 through the passageway using forceps. Alternatively, the wound packing means 278 and the suction drain 245 may be manufactured as a single piece in sterile conditions and then be stored in an aseptic package until ready for use. In other embodiments, the distal end portion 245 a′ of the suction drain 245 may be placed adjacent or close to the wound packing means 278 in the area of the wound 260. The preferred means of placement of the suction drain 245 relative to the wound packing means 278 is dependent upon the type of wound 260, the wound packing means 278, and the type of treatment desired. Referring to FIG. 3 as an example, it is therefore to be noted that in some embodiments of this third aspect of the first version of the invention, the wound treatment device 215 may utilize a suction drain 245 without utilizing wound packing means 278, while in other embodiments a suction drain 245 may be utilized with wound packing means 278. In addition, in other embodiments of this first version of the invention, the wound treatment device 215 may utilize wound packing means 278 without utilizing a suction drain 245, while in other embodiments wound packing means 278 may be utilized with a suction drain 245.

In the embodiment of the first version of the invention illustrated in FIG. 3, the vacuum system 250, which in conjunction with the wound treatment device 215 also represents a fourth aspect of this first version of the invention, is generally comprised of a suction bulb 281 having an inlet port 282 and an outlet port 283, a bulb connection tubing member 284, an exhaust tubing member 285, an exhaust control valve 286, a filter 287, and a supplemental vacuum system (illustrated schematically and generally designated 250 a). In this embodiment, the suction bulb 281 is a hollow sphere that may be used to produce a supply of reduced pressure for use with the wound treatment device 215. In addition, the suction bulb 281 may also be used to receive and store fluid aspirated from the wound 260. The inlet port 282 of the suction bulb 281 is connected to one end of the bulb connection tubing member 284, which is also the reduced pressure supply means 240 in this embodiment. The connection tubing member 284 is connected by suction drain connection means to the top drain portion 245 b at its other end in a manner so that the interior volume of the suction bulb 281 is in fluid communication with the suction drain 245. In this embodiment, the bulb connection tubing member 284 is sufficiently flexible to permit movement of the bulb connection tubing member 284, but is sufficiently rigid to resist constriction when reduced pressure is supplied to the suction drain 245 or when the location of the wound 260 is such that the patient must sit or lie upon the bulb connection tubing member 284 or upon the wound treatment device 215. The outlet port 283 of the suction bulb 281 is connected to the exhaust tubing member 285. In this embodiment, the exhaust tubing member 285 is sufficiently flexible to permit movement of the exhaust tubing member 285, but is sufficiently rigid to resist constriction when reduced pressure is supplied to the suction drain 245. The inlet port 282 of the suction bulb 281 may be connected to the bulb connection tubing member 284 and the outlet port 283 of the suction bulb 281 may be connected to the exhaust tubing member 285 using any suitable means, such as by welding, fusing, adhesives, clamps, or any combination of such means. In addition, in some embodiments, which are the preferred embodiments, the suction bulb 281, the bulb connection tubing member 284, and the exhaust tubing member 285 may be fabricated as a single piece. In the illustrated embodiment, the exhaust control valve 286 and the filter 287 are operably connected to the exhaust tubing member 285. In this embodiment, the exhaust control valve 286 is used to regulate the flow of fluids (gases and liquids) to and from the suction bulb 281 and the supplemental vacuum system 250 a. In embodiments of the invention that do not have a supplemental vacuum system 250 a, the exhaust control valve 286 regulates flow of fluids to and from the suction bulb 281 and the outside atmosphere. Generally, the exhaust control valve 286 allows fluids to flow out of the suction bulb 281 through the outlet port 283, but not to flow in the reverse direction unless permitted by the user of the appliance 210. Any type of flow control valve may be used as the exhaust control valve 286, as long as the valve is capable of operating in the anticipated environment involving reduced pressure and wound 260 exudate. Such valves are well known in the relevant art, such as sprung and unsprung flapper-type valves and disc-type valves. In this embodiment, the filter 287 is operably attached to the exhaust tubing member 285 between the outlet port 283 of the suction bulb 281 and the exhaust control valve 286. The filter 287 prevents potentially pathogenic microbes or aerosols from contaminating the exhaust control valve 286 (and supplemental vacuum system 250 a), and then being vented to atmosphere. The filter 287 may be any suitable type of filter, such as a micropore filter. In other embodiments, the filter 287 may also be a hydrophobic filter that prevents any exudate from the wound 260 from contaminating the exhaust control valve 286 (and the supplemental vacuum system 250 a) and then being vented to atmosphere. In still other embodiments, the filter 287 may perform both functions. It is to be noted, however, that the outlet port 283, the exhaust control valve 286, the filter 287, or any combination of the exhaust control valve 286 and the filter 287, need not be utilized in connection with the vacuum system 250 in other embodiments of the invention.

In some embodiments of these third and forth aspects of the first version of the invention illustrated in FIG. 3 that do not utilize a supplemental vacuum system 250 a, the suction bulb 281 may be used to produce a supply of reduced pressure in the following manner. First, the user of the appliance 210 appropriately seals all of the component parts of the appliance 210 in the manner described herein. For example, the impermeable overlay 220 is sealed (or placed adjacent) to the body 170 and the suction drain 245 is sealed to the bulb connection tubing member 284 and the surface of the port 227. The user then opens the exhaust control valve 286 and applies force to the outside surface of the suction bulb 281, deforming it in a manner that causes its interior volume to be reduced. When the suction bulb 281 is deformed, the gas in the interior volume is expelled to atmosphere through the outlet port 283, the exhaust tubing member 285, the filter 287, and the exhaust control valve 286. The user then closes the exhaust control valve 286 and releases the force on the suction bulb 286. The suction bulb 281 then expands, drawing fluid from the area of the wound 260 under the wound treatment device 215 into the suction bulb 281 through the suction drain 245 and causing the pressure in such area to decrease. To release the reduced pressure, the user of the appliance 210 may open the exhaust control valve 286, allowing atmospheric air into the interior volume of the suction bulb 281. The level of reduced pressure may also be regulated by momentarily opening the exhaust control valve 286.

The suction bulb 281 may be constructed of almost any fluid impermeable flexible or semi-rigid material that is suitable for medical use and that can be readily deformed by application of pressure to the outside surface of the suction bulb 281 by users of the appliance 210 and still return to its original shape upon release of the pressure. For example, the suction bulb 281 may be constructed of rubber, neoprene, silicone, or other flexible or semi-rigid polymers, or any combination of all such materials. In addition, the suction bulb 281 may be of almost any shape, such as cubical, ellipsoidal, or polygonal. The suction bulb 281 may also be of varying size depending upon the anticipated use of the suction bulb 281, the size of the wound treatment device 215, use of a supplemental vacuum system 250 a, the level of reduced pressure desired, and the preference of the user of the appliance 210. In the embodiment of the invention illustrated in FIG. 3, the supplemental vacuum system 250 a is connected to the exhaust tubing member 285 and is used to provide a supplemental supply of reduced pressure to the suction bulb 281 and wound treatment device 215. In this embodiment, the supplemental vacuum system 250 a may have substantially the same structure, features, characteristics and operation of the various embodiments of the vacuum system 50 of the first version of the invention described above and illustrated in connection with FIG. 2A and FIG. 2B. It is to be noted, however, that the supplemental vacuum system 250 a need not be used in connection with the vacuum system 280 in other embodiments of the invention.

Except as described below, the wound treatment appliance 210 described above and illustrated in connection with FIG. 3 may generally be used in a manner similar to the wound treatment appliance 110 described above and illustrated in connection with FIG. 2A and FIG. 2B. As a result, except as described below, the example of how the embodiment of the wound treatment appliance 110 and the flexible overlay 120 described above and illustrated in connection FIG. 2A may be used in treatment of a wound 160 also applies to the embodiment of the appliance 210 of the third aspect of the first version of the invention described above and illustrated in connection with FIG. 3. In the case of the embodiment illustrated in FIG. 3, however, the wound packing means 278 is placed into the wound 260 prior to placement of the flexible overlay 220 over the portion of the wound 260 to be treated. In addition, the flexible overlay 220 is placed over the wound packing means 278. In embodiments where the distal end portion 245 a′ of a suction drain 245 is placed into the interior volume of, or adjacent to, the wound packing means 278, the distal end portion 245 a′ of the suction drain 245 is also placed in the appropriate position before the flexible overlay 220 is placed over the wound 260. In embodiments utilizing a suction drain 245 without wound packing means 278, the suction drain 245 is installed in the flexible overlay 220 before the flexible overlay 220 is placed over the wound 260.

Another embodiment of the first version of the invention is the wound treatment appliance 310 illustrated in FIG. 4. FIG. 4 also illustrates another example of how the embodiment of the flexible overlay 20 described above and illustrated in connection with FIG. 1A may be used to provide reduced pressure treatment for a wound 360 on the body 370 of a patient. In this embodiment, the wound treatment appliance 310 is comprised of a flexible overlay 320 and a vacuum system, generally designated 350, that is operably connected to, and provides a supply of reduced pressure to, the flexible overlay 320. In addition, in this embodiment, the vacuum system 350 is further comprised of a reduced pressure supply source, generally designated 330, which is described in more detail below, and reduced pressure supply means, generally designated 340, which are described in more detail below. In this embodiment, the reduced pressure supply means 340 are used to connect the reduced pressure supply source 330 to the flexible overlay 320 in a manner so that reduced pressure is supplied to the area under the flexible overlay 320, as described in more detail below. In the embodiment of the first version of the invention illustrated in FIG. 4, the flexible overlay 320 has substantially the same structure, features and characteristics as the flexible overlay 20 described above and illustrated in connection with FIG. 1A. It is to be noted, however, that in other embodiments of this first version of the invention, the flexible overlay 320 may have substantially the same structure, features and characteristics as any embodiment of all of the flexible overlays 20, 20 a, 20 b of the first version of the invention described above and illustrated in connection with FIG. 1A, FIG. 1B, and FIG. 1C, respectively. In this example, the flexible overlay 320 is placed over and encloses the entire wound 360, which is at the distal end of an amputated limb. It is to be noted that in other embodiments, the appliance 310 may also be comprised of tissue protection means 375, which may be substantially the same as the tissue protection means 175 of the first version of the invention described above and illustrated in connection with FIG. 2A. In other embodiments, the appliance 310 may also be comprised of wound packing means (not illustrated), which may be substantially the same as the wound packing means 278 of the first version of the invention described above and illustrated in connection with FIG. 3.

In the embodiment of the first version of the invention illustrated in FIG. 4, the reduced pressure supply source 330 of the vacuum system 350, which produces a source of reduced pressure or suction that is supplied to the flexible overlay 320, includes a small, portable vacuum pump 331, a filter 333, and a power source (not illustrated) that is contained within the housing for the portable vacuum pump 331. In the illustrated embodiment, predetermined amounts of suction or reduced pressure are produced by the portable vacuum pump 331. The portable vacuum pump 331 is preferably controlled by a control device (not illustrated) that is also located within the housing for the portable vacuum pump 331, which may provide substantially the same functions as the control device 132 of the first version of the invention described above and illustrated in connection with FIG. 2A and FIG. 2B. Except for its smaller size, the portable vacuum pump 331 may operate in substantially the same manner as the vacuum pump 131 of the first version of the invention described above and illustrated in connection with FIG. 2A and FIG. 2B. In the embodiment illustrated in FIG. 4, the filter 333 may have the same structure, features, characteristics and operation, and provide substantially the same functions, as the filter 133 of the first version of the invention described above and illustrated in connection with FIG. 2A and FIG. 2B. The power source may be any source of energy currently known in the art or that may be developed in the art in the future that may be used to power the portable vacuum pump 331. For example, in some embodiments, the power source may be a fuel cell or battery. In the illustrated embodiment, the filter 333 is rigidly connected to the portable vacuum pump 331. It is to be noted that in other embodiments of the first version of the invention, the reduced pressure supply source 330 may not have a filter 333.

In the embodiment of the first version of the invention illustrated in FIG. 4, the reduced pressure supply means 340 of the vacuum system 350, which is used to connect the reduced pressure supply source 330 to a port 327 on the flexible overlay 320 so that reduced pressure is supplied to the area of the wound 360 under the flexible overlay 320, is comprised of at least one 25 tubing member 341. In this embodiment, the at least one tubing member 341 is a rigid tubing member. In other embodiments, the at least one tubing member 341 may be sufficiently flexible to permit movement of the at least one tubing member 341, but is sufficiently rigid to resist constriction when reduced pressure is supplied to the port 327 or when the location of the wound 360 is such that the patient must sit or lie upon the at least one tubing member 341 or upon the flexible overlay 320. In the embodiment illustrated in FIG. 4, the at least one tubing member 341 is connected to the port 327 by inserting one end of the at least one tubing member 341 into an opening 328 in the port 484 and sealing (such as with an adhesive) the at least one tubing member 341 to the port 327. It is to be noted that in other embodiments, the at least one tubing member 341 may be connected to the port 327 using any suitable means currently known in the relevant art or developed in the relevant art in the future. Examples include the suction drain connection means of the first version of the invention discussed above and illustrated in connection with FIG. 3. Similar means may be used to connect the other end of the at least one tubing member 341 to the reduced pressure supply source 330 providing the reduced pressure. In other embodiments of this first version of the invention, the reduced pressure supply means 340 may further comprise a fluid collection system (not illustrated), which may generally have the same structure, features, characteristics and operation, and perform the same functions, as the fluid collection system 142 of the first version of the invention described above and illustrated in connection with FIG. 2A and FIG. 2B.

An embodiment of a second version of the invention is the wound treatment appliance 410 illustrated in FIG. 5. In this embodiment, the appliance 410 is comprised of a wound treatment device 415, which is further comprised of an impermeable overlay 420, a collection chamber 490 to receive and hold fluid aspirated from the wound 460, collection chamber attachment means to operably attach the collection chamber 490 to the overlay 420, as described in more detail below, and reduced pressure supply means, generally designated 440, which are described in more detail below. In this embodiment, the impermeable overlay 420 is adapted to be placed over and enclose all or a portion of the wound 460 in the same manner as the flexible overlay 20 described in detail above and illustrated in connection with FIG. 1A. It is to be noted, however, that the impermeable overlay 420 illustrated in FIG. 5 is shown in position on the body 470 over the wound 460, but not in its collapsed state. In the illustrated embodiment, and except as described in more detail below, the impermeable overlay 420 has substantially the same structure, features and characteristics as the flexible overlay 20 described in detail above and illustrated in connection with FIG. 1A. In the various embodiments of this second version of the invention, except as described in more detail below, the impermeable overlay 420 may have substantially the same structure, features, characteristics and operation as the embodiments of the flexible overlays 20, 20 a, 20 b, 120, 220 described in more detail above and illustrated in connection with FIG. 1A, FIG. 1B, FIG. 1C, FIG. 2A, and FIG. 3, respectively. In addition, the impermeable overlay 420 may be almost any type of semi-rigid or rigid wound covering apparatus currently known in the relevant art or that may be developed in the relevant art in the future that has a port and is designed to cover and enclose a wound and maintain reduced pressure in the area of the wound under the wound covering apparatus. For example, the impermeable overlay 420 may generally have substantially the same structure, features and characteristics as the embodiments of the rigid or semi-rigid generally conically-shaped or cup-shaped wound covers described in U.S. patent application Ser. No. 10/652,100, which was filed by the present inventor with the U.S. Patent and Trademark Office on Aug. 28, 2003, and U.S. patent application entitled “Improved Reduced Pressure Wound Treatment Appliance,” which was filed by the present inventor with the U.S. Patent and Trademark Office on or about Dec. 30, 2004, the disclosures of which are incorporated herein by reference. In the illustrated embodiment, reduced pressure supply means, generally designated 440, which are described in more detail below, are used to operably connect the collection chamber 490 to a reduced pressure supply source, generally designated 430, which is described in more detail below, that provides a supply of reduced pressure to the collection chamber 490, so that the volume within the collection chamber 490 and under the impermeable overlay 420 in the area of the wound 460 to be treated are supplied with reduced pressure by the reduced pressure supply source 430. Together, the reduced pressure supply means 440 and the reduced pressure supply source 430 comprise a vacuum system, generally designated 450. In the various embodiments of this second version of the invention, except as described in more detail below, the reduced pressure supply means 440 used to connect the reduced pressure supply source 430 to the collection chamber 490 may have substantially the same structure, features, characteristics and operation as the reduced pressure supply means 140, 240, 340 described above and illustrated in connection with FIG. 2A, FIG. 2B, FIG. 3, and FIG. 4, respectively. In addition, in the various embodiments of this second version of the invention, except as described in more detail below, the reduced pressure supply source 430 used to provide the supply of reduced pressure to the collection chamber 490 may have substantially the same structure, features, characteristics and operation as the reduced pressure supply source 130, 280, 330 described above and illustrated in connection with FIG. 2A, FIG. 2B, FIG. 3, and FIG. 4, respectively.

In the embodiment of the appliance 410 illustrated in FIG. 5, the collection chamber 490 is approximately cylindrical in shape. In other embodiments, the collection chamber 490 may have other shapes. For example, the collection chamber may be shaped approximately as a sphere, ellipsoid, cube, polyhedron, or other shape or combination of such shapes, as long as the collection chamber 490 has an interior volume to receive and hold fluid aspirated from the wound 460. The collection chamber 490 may also be of almost any size. For example, the collection chamber 490 may be relatively small where the wound 460 is expected to aspirate only a small volume of fluid. On the other hand, the collection chamber 490 may be relatively large where it is expected that the wound 460 will aspirate a large volume of fluid. As a result, the preferred size of the collection chamber 490 is dependent upon the size of the wound 460 to be treated, the size of the impermeable overlay 420, the type of wound 460 to be treated, and the preference of the user of the appliance 410. In the various embodiments of this second version of the invention, the collection chamber 490 may be comprised of almost any medical grade material that is currently known in the art or that may be developed in the art in the future, as long as such material is fluid-impermeable and suitable for purposes of wound treatment (e.g., can be sterilized and does not absorb significant amounts of wound 460 exudate). For example, the collection chamber 490 may be comprised of rubber (including neoprene) and polymer materials, such as silicone, silicone blends, silicon substitutes, polyvinyl chloride, polycarbonates, polyester-polycarbonate blends, or a similar polymer, or combinations of all such materials. It is to be noted that the collection chamber 490 may have a rigid or semi-rigid structure in some embodiments. In other embodiments, the collection chamber 490 may be more flexible so that it can be squeezed in a manner similar to the suction bulb 281, as described above and illustrated in connection with FIG. 3. Although the collection chamber 490 may be constructed of a material different from the material comprising the impermeable overlay 420 in various embodiments of the invention, the collection chamber 490 is preferably constructed from the same material comprising the impermeable overlay 420. The collection chamber 490 may be constructed using any suitable means currently known in the art or that may be developed in the art in the future. For example, a collection chamber 490 constructed of silicone may be manufactured by means of injection molding.

In the various embodiments of this second version of the invention, the collection chamber attachment means operably attaches the collection chamber 490 to the impermeable overlay 420 in a manner so that exudate and reduced pressure are permitted to flow between the collection chamber 490 and the volume under the impermeable overlay 420 in the area of the wound 460. Also, in the various embodiments of the second version of the invention, as illustrated by the appliance 410 in FIG. 5, the collection chamber 490 is positioned approximately adjacent to the impermeable overlay 420 on the side of the impermeable overlay 420 opposite the wound 460. Although the collection chamber 490 and the collection chamber attachment means are positioned approximately at the apex of the impermeable overlay 420 in the illustrated embodiment, in other embodiments the collection chamber 490 and collection chamber attachment means may be positioned at almost any location on the surface of the impermeable overlay 420 opposite the wound 460, as long as the collection chamber 490 and collection chamber attachment means do not materially interfere with the operation of the impermeable overlay 420. As illustrated in FIG. 5, the collection chamber attachment means may be a rigid or semi-rigid connecting member 491 between the collection chamber 490 and the impermeable overlay 420. In this embodiment, the connecting member 491 is approximately cylindrical in shape and has a port 492 therein, which is also approximately cylindrical in shape and extends between the collection chamber 490 and the impermeable overlay 420 so that fluids can flow between the collection chamber 490 and the impermeable overlay 420. In other embodiments, the connecting member 491 and the port 492 may be of almost any shape or combination of shapes. For example, the connecting member 491 and the port 492 may be shaped approximately as a sphere, ellipsoid, cube, polygon, paraboloid, or any other shape or combination of shapes, as long as the connecting member 491 provides a rigid or semi-rigid connection between the collection chamber 490 and the impermeable overlay 420 that is adequate to support the collection chamber 490 when it is filled with exudate from the wound 460, and the port 492 is of a size and shape adequate to allow the flow of exudate from the wound 460 between the collection chamber 490 and the impermeable overlay 420. For example, the collection chamber 490 in some embodiments may have approximately the same outside diameter as the connecting member 491, as illustrated by the phantom lines 493 in FIG. 5. The connecting member 491 may generally be constructed of any material that is suitable for construction of the collection chamber 490 or the impermeable overlay 420, and is preferably constructed from the same materials as the collection chamber 490 and the impermeable overlay 420. In various embodiments, the collection chamber 490 and the impermeable overlay 420 may be connected to the connecting member 491 using any suitable means, such as by adhesives, welding, fusing, clamps, and other fastening means or combinations of such means. In yet other embodiments, the collection chamber 490, the impermeable overlay 420, and the connecting member 491 may be fabricated as a single piece. In still other embodiments, one or more of the connections between the collection chamber 490, the impermeable overlay 420, and the connecting member 491 may provide for removing one component from another to empty fluid from the collection chamber 490. For example, the collection chamber 490, the impermeable overlay 420, and the connecting member 491 may each be threaded at their points of connection so that they can be screwed together and then unscrewed when desired. In still other embodiments, the collection chamber 490 and the impermeable overlay 420 may be directly connected together without a connecting member 491, as long as the connection allows fluid to flow between the collection chamber 490 and the impermeable overlay 420. Such connection may be made using any of the means described above in this paragraph.

In some embodiments of this second version of the invention, as illustrated in FIG. 5, the connecting member 491, as the collection chamber attachment means, may be further comprised of a flow control means, which is described in more detail below, operably positioned between the collection chamber 490 and the impermeable overlay 420. In these embodiments, the flow control means permits fluid aspirated from the wound 460 to flow from the volume under the impermeable overlay 420 in the area of the wound 460 through the port 492 into the collection chamber 490, but not in the opposite direction. In the illustrated embodiment, the flow control means is comprised of a flapper-type valve 494. In this embodiment, the valve 494 has two flapper members 494 a that are hinged at their distal end to a portion of the connecting member 491, and the flapper members 494 a are of a shape and size adapted to substantially close the port 492 when they are positioned in the closed position. In other embodiments, the flow control means may be comprised of a disc-type valve, wherein the disc of the valve moves with the flow of fluids and contacts a seat disposed around the perimeter of the port when the flow of fluids is misdirected, so that the port is sealed closed and prevents fluid flow in the wrong direction. In some embodiments, as illustrated in FIG. 5, the collection chamber 490 may be further comprised of a shroud 495 (illustrated by the phantom lines) that extends from a portion of the collection chamber 490 to the impermeable shield 420. In these embodiments, the shroud 495 is approximately tubular in shape. In other embodiments, the shroud 495 may have other shapes. The shroud 495 generally provides additional support for the collection chamber 490 and may also provide for a more aesthetically pleasing appearance for the appliance 410. In addition, in the embodiment of the appliance 410 illustrated in FIG. 5, the reduced pressure supply means 440 is connected to the collection chamber 490 by means of a stopper 445 adapted to fit into an opening 496 in the collection chamber 490. The stopper 445 forms a seal with the portion of the collection chamber 490 adjacent to the opening 496 so that reduced pressure can be maintained within the interior volume of the collection chamber 490. In this embodiment, the reduced pressure supply means is comprised of a tubular member 441 that is positioned in a port 446 in the stopper 445 at one end and is connected to the reduced pressure supply source 430 at the other end.

The embodiment of the appliance 410 illustrated in FIG. 5 may be used to treat a wound 460 on a body 470 using a method comprising the following steps. First, the wound treatment device 415 is positioned on the body 470 over the area of the wound 460 to be treated. Next, the vacuum system 450 is operably connected to the collection chamber 490. The impermeable overlay 420 may then be collapsed in the approximate direction of the wound 460 when reduced pressure is supplied to the volume under the impermeable overlay 420 in the area of the wound 460 so that an approximately hermetic seal (as illustrated and described in more detail above in connection with FIG. 2A) is formed between the impermeable overlay 420 and the body 470 in the area of the wound 460. Next, reduced pressure is maintained in the volume of the impermeable overlay 420 in the area of the wound 460 until the area of the wound 460 being treated has progressed toward a selected stage of healing. In other embodiments, the method may further comprise the step of placing tissue protection means 475, which may be substantially the same as the tissue protection means 175, as described above and illustrated in connection with FIG. 2A, on the tissue 471 of the body 470 that is to be approximately adjacent to the impermeable overlay 420, such step being performed prior to positioning the impermeable overlay 420 over the area of the wound 460 to be treated. In yet other embodiments, the method further comprises the step of placing wound packing means (not illustrated), which may be substantially the same as the wound packing means 278, as described above and illustrated in connection with FIG. 3, between the wound 460 and the impermeable overlay 420 in the area of the wound 460 to be treated, such step being performed prior to positioning the impermeable overlay 420 over the area of the wound 460 to be treated. In still other embodiments, the reduced pressure under the impermeable overlay 420 in the area of the wound 460 is in the range from approximately 20 mm of Hg below atmospheric pressure to approximately 125 mm of Hg below atmospheric pressure. In other embodiments, the reduced pressure is applied in a cyclic nature, the cyclic nature providing alternating time periods of application of reduced pressure and without application of reduced pressure. In yet other embodiments, the method is further comprised of the step of emptying any fluid collected in the collection chamber 490. This step may be performed after the impermeable overlay 420 is collapsed in the approximate direction of the wound 460 and may also be performed before or after the area of the wound 460 being treated has progressed toward a selected stage of healing.

Another embodiment of the second version of the invention is the wound treatment appliance 510 illustrated in FIG. 6. In this embodiment, the appliance 510 is comprised of an impermeable overlay 520, a collection chamber 590 to receive and hold fluid aspirated from a wound (not shown), collection chamber attachment means to operably attach the collection chamber 590 to the overlay 520, as described in more detail below, and reduced pressure supply means, generally designated 540, which are described in more detail below. In this embodiment, the impermeable overlay 520 is adapted to be placed over and enclose all or a portion of a wound in the same manner as the flexible overlay 20 a described in detail above and illustrated in connection with FIG. 1B. It is to be noted that the impermeable overlay 520 illustrated in FIG. 6 is not shown in its collapsed state. In the illustrated embodiment, and except as described in more detail below, the impermeable overlay 520 has substantially the same structure, features and characteristics as the flexible overlay 20 a described in detail above and illustrated in connection with FIG. 1B. In other embodiments, the impermeable overlay 520 may be of other shapes and have other features. For example, the impermeable overlay 520 may be of the shape and have the features illustrated and described above in connection with the appliance 10 b of FIG. 1C. In the embodiment illustrated in FIG. 6, the reduced pressure supply means 540, which are described in more detail below, may be used to operably connect the collection chamber 590 to a reduced pressure supply source (not shown), which is described in more detail below, that provides a supply of reduced pressure to the collection chamber 590, so that the volume within the collection chamber 590 and under the impermeable overlay 520 in the area of the wound to be treated are supplied with reduced pressure by the reduced pressure supply source. Together, the reduced pressure supply means 540 and the reduced pressure supply source comprise a vacuum system, generally designated 550. In this embodiment of the second version of the invention, except as described in more detail below, the reduced pressure supply means 540 used to connect the reduced pressure supply source to the collection chamber 590 may have substantially the same structure, features, characteristics and operation as the reduced pressure supply means 140, 240, 340 described above and illustrated in connection with FIG. 2A, FIG. 2B, FIG. 3, and FIG. 4, respectively. In addition, in this embodiment of the second version of the invention, except as described in more detail below, the reduced pressure supply source used to provide the supply of reduced pressure to the collection chamber 590 may have substantially the same structure, features, characteristics and operation as the reduced pressure supply source 130, 280, 330 described above and illustrated in connection with FIG. 2A, FIG. 2B, FIG. 3, and FIG. 4, respectively. The embodiment of the appliance 510 illustrated in FIG. 6 may be used to treat a wound on a body using substantially the same method described above in connection with the appliance 410 illustrated in FIG. 5.

In the embodiment illustrated in FIG. 6, the collection chamber 590 is positioned approximately adjacent to the impermeable flexible overlay 520 on the side of the impermeable flexible overlay 520 opposite the wound. In this embodiment, the collection chamber attachment means, as described in more detail below, is comprised of a membrane 591. In this embodiment, the membrane 591 acts as a barrier separating the collection chamber 590 and the impermeable flexible overlay 520, so that the membrane 591 acts as a portion of the surface of the collection chamber 590 and a portion of the surface of the impermeable flexible overlay 520. In addition, the membrane 591 has at least one port 592 therein so that the volume within the collection chamber 590 is in fluid communication with the volume under the impermeable flexible overlay 520 in the area of the wound. It is to be noted that there may be more than one port 592 in other embodiments. The number of ports 492 is generally dependent upon the size and shape of the collection chamber 590, the size and shape of the impermeable flexible overlay 520, the anticipated amount of exudate to be aspirated from the wound, the level of reduced pressure to be utilized, and the individual preference of the user of the appliance 510. In embodiments where the impermeable flexible overlay 520 has an approximately elongated conical shape, as illustrated in FIG. 6, the impermeable flexible overlay 520 may have a base end opening 521 and a top end opening 524 opposite the base end opening 521. In these embodiments, the base end opening 521 may have an either approximately circular shape or approximately elliptical shape sized to be placed over and enclose the area of the wound to be treated. The top end opening 524 may have either an approximately circular shape or approximately elliptical shape. In the illustrated embodiments, the membrane 591 is adapted to be of the same shape and size as the top end opening 524 and the membrane 591 is positioned so that it is attached to the entire perimeter of the top end opening 524 and covers the entire top end opening 524. The membrane 591 may be attached to the perimeter of the top end opening 524 by any suitable means currently known in the relevant art or developed in the art in the future. Examples of such means include welding or fusing the membrane 591 to the perimeter of the top end opening 524. Alternatively, the membrane 591 may be fabricated as a single piece with the impermeable flexible overlay 520.

In the embodiment of the appliance 510 illustrated in FIG. 6, the collection chamber 590 has an approximately elongated conical shape, a chamber bottom end opening 593, and a reduced pressure supply port 596 positioned at the apex of the collection chamber 590 opposite the chamber bottom end opening 593. The reduced pressure supply port 596 may be used to operably connect the reduced pressure supply means 540 to the collection chamber 590. In some embodiments, a micropore or hydrophobic filter or both (not shown) may be operably positioned within the reduced pressure supply port 596 or the connection with the reduced pressure supply means 540 to retain the exudate from the wound within the collection container 590 or to prevent exudate from contaminating portions of the vacuum system 550, or both. In the illustrated embodiment, the chamber bottom end opening 593 is adapted to be of approximately the same size and shape as the top end opening 524 of the impermeable flexible overlay 520. In other embodiments, the collection chamber 590 may be of other shapes and sizes and its bottom end opening 593 may not necessarily be of the same size and shape as the top end opening 524 of the impermeable flexible overlay 520. In all embodiments, however, the collection chamber 590 is attached to the membrane 591 in a manner so that the membrane 591 acts as a portion of the surface of the collection chamber 590 and so that the volume within the collection chamber 590 is airtight, except for the at least one port 592 and the reduced pressure supply port 596. In the preferred embodiment, the collection chamber 590 and the impermeable flexible overlay 520 have the shapes illustrated in FIG. 6. The membrane 591 may be attached to the perimeter of the chamber bottom end opening 593 by any suitable means currently known in the relevant art or developed in the art in the future. Examples of such means include welding or fusing the membrane 591 to the perimeter of the chamber bottom end opening 593. Alternatively, the membrane 591 or the impermeable flexible overlay 520, or both, may be fabricated as a single piece with the collection chamber 590. The preferred shapes and sizes of the collection chamber 590 and the impermeable flexible overlay 520 are dependent upon the size and type of wound to be treated, the area of the body on which the wound is positioned, the level of reduced pressure to be utilized, the amount of collapse of the impermeable flexible overlay 520 desired, and the preference of the user of the appliance 510. In this embodiment of the second version of the invention, the collection chamber 590 may be comprised of almost any medical grade material that is currently known in the art or that may be developed in the art in the future, as long as such material is fluid-impermeable and suitable for purposes of wound treatment (e.g., can be sterilized and does not absorb significant amounts of wound exudate). For example, the collection chamber 590 may be comprised of rubber (including neoprene) and flexible polymer materials, such as silicone, silicone blends, silicone substitutes, polyvinyl chloride, polycarbonates, polyester-polycarbonate blends, or a similar polymer, or combinations of all such materials. It is to be noted that the collection chamber 590 may have a rigid or semi-rigid structure in some embodiments. In other embodiments, the collection chamber 590 may be more flexible so that it can be squeezed in a manner similar to the suction bulb 281, as described above and illustrated in connection with FIG. 3. Although the collection chamber 590 may be constructed of a material different from the material comprising the impermeable overlay 520 in various embodiments of the invention, the collection chamber 590 is preferably constructed from the same material comprising the impermeable overlay 520. The collection chamber 590 may be constructed using any suitable means currently known in the art or that may be developed in the art in the future. For example, a collection chamber 590 constructed of silicone may be manufactured by means of injection molding.

In the embodiment of the second version of the invention illustrated in FIG. 6, the membrane 591 and its means of being sealed to the perimeters of the top end opening 524 and the chamber bottom end opening 593, together as collection chamber attachment means, operably attach the collection chamber 590 to the impermeable overlay 520 in a manner so that exudate and reduced pressure are permitted to flow between the collection chamber 590 and the volume under the impermeable overlay 520 in the area of the wound. In the embodiment illustrated in FIG. 6, the at least one port 592 is approximately cylindrical in shape and extends between the collection chamber 590 and the impermeable overlay 520 so that fluids can flow between the collection chamber 590 and the impermeable overlay 520. In other embodiments, the at least one port 592 may be of almost any shape or combination of shapes. In some embodiments of this second version of the invention, as illustrated in FIG. 6, the membrane 591 comprising the collection chamber attachment means may be further comprised of a flow control means, which is described in more detail below, operably connected with the at least one port 592 and positioned between the collection chamber 590 and the impermeable overlay 520. In these embodiments, the flow control means permits fluid aspirated from the wound to flow from the volume under the impermeable overlay 520 in the area of the wound 560 through the at least one port 592 into the collection chamber 590, but not in the opposite direction. In the illustrated embodiment, the flow control means is comprised of a flapper-type valve 594. In this embodiment, the valve 594 has two flapper members 594 a that are hinged at their distal end to a portion of the membrane 491 or supporting structure surrounding the at least one port 492 and the flapper members 594 a are of a shape and size adapted to substantially close the at least one port 592 when they are positioned in the closed position. In other embodiments, the flow control means may be comprised of a disc-type of valve. 

What is claimed is:
 1. An apparatus for administering reduced pressure treatment to a wound on a body, comprising: a flexible overlay positionable over the wound and adapted to maintain reduced pressure under the flexible overlay, the flexible overlay configured to form a seal surrounding the wound and having at least one opening therein; a vacuum source configured to provide reduced pressure through the opening to a space under the overlay; a conduit for connecting the overlay to the vacuum source; a hydrophobic filter positioned at the opening, wherein the hydrophobic filter is configured to retain wound exudate in the space under the overlay; wherein the flexible overlay defines at least in part a collection chamber configured such that exudate from the wound can flow into the collection chamber and is retained therein, but the wound exudate within the collection chamber is prevented from flowing past the hydrophobic filter; and further comprising a membrane that acts as a barrier separating the collection chamber and the flexible overlay, so that the membrane acts as a portion of the surface of the collection chamber and a portion of the surface of the flexible overlay.
 2. An apparatus for administering reduced pressure treatment to a wound on a body, comprising: a flexible overlay positionable over the wound and adapted to maintain reduced pressure under the flexible overlay, the flexible overlay configured to form a seal surrounding the wound and having at least one opening therein; a vacuum source configured to provide reduced pressure through the opening to a space under the overlay; a conduit for connecting the overlay to the vacuum source; a hydrophobic filter positioned at the opening, wherein the hydrophobic filter is configured to retain wound exudate in the space under the overlay; wherein the flexible overlay defines at least in part a collection chamber configured such that exudate from the wound can flow into the collection chamber and is retained therein, but the wound exudate within the collection chamber is prevented from flowing past the hydrophobic filter; and further comprising a membrane configured to prevent wound exudate within the collection chamber from flowing back into the wound.
 3. The apparatus of claim 2, wherein the membrane comprises at least one one-way valve.
 4. The apparatus of claim 1, further comprising a tissue protection member beneath the overlay.
 5. The apparatus of claim 4, wherein adhesive is applied to the tissue protection member.
 6. The apparatus of claim 1, further comprising a wound packing member beneath the overlay.
 7. The apparatus of claim 6, wherein the wound packing member is an absorbable matrix.
 8. The apparatus of claim 1, wherein the chamber is integrally formed with the overlay.
 9. The apparatus of claim 1, further comprising a port supported by the overlay adapted to connect to the vacuum source.
 10. The apparatus of claim 1, further comprising an adhesive applied to the flexible overlay.
 11. The apparatus of claim 1, wherein the flexible overlay comprises a semi-rigid material configured to maintain its shape in the absence of vacuum.
 12. The apparatus of claim 11, wherein the opening in the flexible overlay is provided at an apex of the flexible overlay and the flexible overlay comprises a base opening sized to substantially encompass the wound.
 13. The apparatus of claim 12, wherein the flexible overlay has a shape selected from the group consisting of bell-shaped, conical-shaped, and cup-shaped.
 14. The apparatus of claim 12, wherein the collection chamber is positioned below the apex of the flexible overlay and above the base opening.
 15. A method of treating a wound, comprising: positioning a flexible overlay over the wound, the flexible overlay forming a seal surrounding the wound, wherein the flexible overlay comprises a membrane that prevents wound exudate within the chamber from flowing back to the wound; supplying a source of reduced pressure to the overlay through an opening in the overlay, wherein a hydrophobic filter is positioned at the opening; drawing wound exudate from the wound into a collection chamber defined at least in part by the flexible overlay; and preventing wound exudate within the chamber from flowing past the hydrophobic filter.
 16. The method of claim 15, wherein supplying a source of reduced pressure to the overlay comprises providing a conduit coupled to a port on the flexible overlay.
 17. The method of claim 16, wherein supplying a source of reduced pressure comprises connecting a vacuum source to the conduit.
 18. The method of claim 15, further comprising positioning a tissue protection member adjacent the wound.
 19. The method of claim 15, further comprising positioning a wound packing member between the chamber and the wound.
 20. The method of claim 15, wherein a portable vacuum pump supplies reduced pressure to the overlay.
 21. The method of claim 15, wherein the membrane comprises a valve.
 22. The method of claim 15, further comprising preventing wound exudate within the chamber from flowing back into the wound.
 23. An appliance for administering reduced pressure treatment to a wound on a body, the appliance comprising: an impermeable flexible overlay sized to be placed over and enclose the area of the wound to be treated and adapted to maintain reduced pressure in the volume under the impermeable flexible overlay in the area of the wound; a collection chamber to receive and hold fluid aspirated from the wound; collection chamber attachment means to operably attach the collection chamber to the impermeable flexible overlay, wherein reduced pressure and the fluid are permitted to flow between the collection chamber and the impermeable flexible overlay; and reduced pressure supply means to operably connect the collection chamber to a reduced pressure supply source that provides a supply of reduced pressure to the collection chamber, so that the volume within the collection chamber and under the impermeable overlay in the area of the wound to be treated are supplied with reduced pressure by the reduced pressure supply source; wherein: the impermeable flexible overlay collapses in the approximate direction of the area of the wound to be treated when reduced pressure is supplied to the volume under the impermeable flexible overlay in the area of the wound, such collapse causing the formation of an approximately hermetic seal between the impermeable flexible overlay and the body in the area of the wound; the collection chamber is positioned approximately adjacent to the impermeable flexible overlay on the side of the impermeable flexible overlay opposite the wound; the collection chamber attachment means comprises a membrane; the membrane acts as a barrier separating the collection chamber and the impermeable flexible overlay, so that the membrane acts as a portion of the surface of the collection chamber and a portion of the surface of the impermeable flexible overlay; the membrane has at least one port therein so that the volume within the collection chamber is in fluid communication with the volume under the impermeable flexible overlay in the area of the wound.
 24. The appliance of claim 23, wherein: the impermeable flexible overlay has an approximately conical shape or approximately elongated conical shape and comprises: a base end opening having an either approximately circular shape or approximately elliptical shape, wherein the approximately circularly shaped or approximately elliptically-shaped base end opening is sized to be placed over and enclose the area of the wound to be treated; and a top end opening opposite the base end opening, wherein the top end opening has either an approximately circular shape or approximately elliptical shape; and the membrane is sized to be of the same shape and size as the top end opening and the membrane is positioned so that it is attached to the entire perimeter of the top end opening and covers the entire top end opening.
 25. The appliance of claim 24, wherein the collection chamber has an approximately conical shape or approximately elongated conical shape and further comprises: a chamber bottom end opening having an either approximately circular shape or approximately elliptical shape, wherein the approximately circularly shaped or approximately elliptically-shaped chamber bottom end opening is adapted to be of approximately the same size and shape as the top end opening of the impermeable flexible overlay; and a reduced pressure supply port positioned at the apex of the collection chamber opposite the chamber bottom end opening; wherein the reduced pressure supply port operably connects the reduced pressure supply means to the collection chamber.
 26. The appliance of claim 25, further comprising a micropore filter, a hydrophobic filter, or both, operably connected to the reduced pressure supply port.
 27. The appliance of claim 23, wherein the collection chamber attachment means further comprises flow control means operably connected with the at least one port, wherein the flow control means permits the fluid to flow from the volume under the impermeable flexible overlay in the area of the wound through the at least one port to the collection chamber, but not in the opposite direction.
 28. The appliance of claim 27, wherein the flow control means comprises a flapper-type valve.
 29. An appliance for administering reduced pressure treatment to a wound on a body, the appliance comprising: a flexible overlay sized to be placed over and enclose the area of the wound to be treated and adapted to maintain reduced pressure in the volume under the flexible overlay in the area of the wound; a collection chamber to receive and hold fluid aspirated from the wound, the collection chamber being attached to the flexible overlay such that reduced pressure and the fluid are permitted to flow through the collection chamber and the flexible overlay; a membrane between the overlay and the collection chamber, the membrane forming a bottom surface of the collection chamber; a port at the top of the collection chamber; one or more conduits that, in operation, couple the port at the top of the collection chamber with a reduced pressure supply source and provide a supply of reduced pressure to the collection chamber so that the volume within the collection chamber and under the overlay in the area of the wound to be treated are supplied with reduced pressure; and a hydrophobic filter positioned at the port to retain exudate from the wound within the collection chamber; wherein: the collection chamber is positioned approximately adjacent to the flexible overlay on the side of the flexible overlay opposite the wound; the membrane acts as a barrier separating the collection chamber and the flexible overlay, so that the membrane acts as a portion of the surface of the collection chamber and a portion of the surface of the flexible overlay; the membrane has at least one port therein so that the volume within the collection chamber is in fluid communication with the volume under the flexible overlay in the area of the wound.
 30. The appliance of claim 29, wherein the membrane is approximately elliptically shaped.
 31. The appliance of claim 29, wherein the appliance has an approximately elliptical shaped opening surrounding the wound.
 32. The appliance of claim 29, wherein a portion of the collection chamber closest to the wound is approximately elliptically shaped.
 33. The appliance of claim 29, wherein the appliance is configured to permit a fluid to flow from the volume under the flexible overlay in the area of the wound through the at least one port to the collection chamber, but not in the opposite direction.
 34. The appliance of claim 33, wherein the membrane comprises a flapper-type valve.
 35. The apparatus of claim 1, wherein the membrane is configured to prevent wound exudate within the collection chamber from flowing back into the wound.
 36. The apparatus of claim 1, wherein the membrane has at least one port therein so that the volume within the collection chamber is in fluid communication with the volume under the flexible overlay in the area of the wound. 